Photoconductive member comprising amorphous germanium, amorphous silicon and nitrogen

ABSTRACT

A photoconductive member comprises a substrate for photoconductive member and a light receiving layer provided on said substrate having a layer constitution in which a first layer region (G) comprising an amorphous material containing germanium atoms and a second layer region (S) exhibiting photoconductivity comprising an amorphous material containing silicon atoms are successively provided from the substrate side, said light receiving layer containing nitrogen atoms.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a photoconductive member having sensitivity toelectromagnetic waves such as light (herein used in a broad sense,including ultraviolet rays, visible light, infrared rays, X-rays,gamma-rays, and the like).

2. Description of the Prior Art

Photoconductive materials, which constitute photoconductive layers insolid state image pickup devices, image forming members forelectrophotography in the field of image formation, or manuscriptreading devices and the like, are required to have a high sensitivity, ahigh SN ratio (photocurrent (I_(p))/dark current (I_(d))), spectralcharacteristics matching to those of electromagnetic waves to beirradiated, a rapid response to light, a desired dark resistance valueas well as no harm to human bodies during usage. Further, in a solidstate image pick-up device, it is also required that the residual imageshould easily be treated within a predetermined time. Particularly, incase of an image forming member for electrophotography to be assembledin an electrophotographic device to be used in an office as officeapparatus, the aforesaid harmless characteristic is very important.

From the standpoint as mentioned above, amorphous silicon (hereinafterreferred to as a-Si) has recently attracted attention as aphotoconductive material. For example, German OLS Nos. 2746967 and2855718 disclose applications of a-Si for use in image forming membersfor electrophotography, and German OLS No. 2933411 discloses anapplication of a-Si for use in a photoelectric transducing readingdevice.

However, under the present situation, the photoconductive members of theprior art having photoconductive layers constituted of a-Si are furtherrequired to be improved in a balance of overall characteristicsincluding electrical, optical and photoconductive characteristics suchas dark resistance value, photosensitivity and response to light, etc.,and environmental characteristics during use such as humidityresistance, and further stability with the lapse of time.

For instance, when the above photoconductive member is applied in animage forming member for electrophotography, residual potential isfrequently observed to remain during use thereof if improvements tohigher photosensitivity and higher dark resistance are scheduled to beeffected at the same time. When such a photoconductive member isrepeatedly used for a long time, there will be caused variousinconveniences such as accumulation of fatigues by repeated uses or socalled ghost phenomenon wherein residual images are formed, or responsecharacteristic will gradually be lowered when used at high speedrepeatedly.

Further, a-Si has a relatively smaller coefficient of absorption of thelight on the longer wavelength side in the visible light region ascompared with that on the shorter wavelength side. Accordingly, inmatching to the semiconductor laser practically applied at the presenttime, the light on the longer wavelength side cannot effectively beutilized, when employing a halogen lamp or a fluorescent lamp as thelight source. Thus, various points remain to be improved.

On the other hand, when the light irradiated is not sufficientlyabsorbed in the photoconductive layer, but the amount of the lightreaching the substrate is increased, interference due to multiplereflection may occur in the photoconductive layer to become a cause for"unfocused" image, in the case when the substrate itself has a highreflectance against the light transmitted through the photoconductivelayer.

This effect will be increased, if the irradiated spot is made smallerfor the purpose of enhancing resolution, thus posing a great problem inthe case of using a semiconductor laser as the light source.

Further, a-Si materials to be used for constituting the photoconductivelayer may contain as constituent atoms hydrogen atoms or halogen atomssuch as fluorine atoms, chlorine atoms etc. for improving theirelectrical, photoconductive characteristics, boron atoms, phosphorusatoms, etc. for controlling the electroconduction type as well as otheratoms for improving other characteristics. Depending on the manner inwhich these constituent atoms are contained, there may sometimes becaused problems with respect to electrical or photoconductivecharacteristics of the layer formed.

That is, for example, in many cases, the life of the photocarriersgenerated by light irradiation in the photoconductive layer formed isinsufficient, or at the dark portion, the charges injected from thesubstrate side cannot sufficiently be impeded.

Further, when the layer thickness is as thick as ten and some microns orhigher, there tend to occur such phenomena as loosening or peeling oflayers off from the substrate surface or formation of cracks in thelayers with lapse of time when left to stand in air after taking outfrom a vacuum deposition chamber for layer formation. These phenomenonwill occur particularly frequently when the substrate is a drum-shapedsubstrate conventionally employed in the field of electrophotography.Thus, there are problems to be solved with respect to stability withlapse of time.

Accordingly, while attempting to improve the characteristics of a-Simaterial per se on one hand, it is also required to make efforts toovercome all the problems as mentioned above in designing of thephotoconductive member on the other hand.

In view of the above points, the present invention contemplates theachievement obtained as a result of extensive studies madecomprehensively from the standpoints of applicability and utility ofa-Si as a photoconductive member for image forming members forelectrophotography, solid state image pick-up devices, reading devices,etc. It has now been found that a photoconductive member having a layerconstitution comprising a light receiving layer exhibitingphotoconductivity, which comprises a-Si, especially an amorphousmaterial containing at least one of hydrogen atom (H) and halogen atom(X) in a matrix of silicon atoms such as so called hydrogenatedamorphous silicon, halogenated amorphous silicon or halogen-containinghydrogenated amorphous silicon (hereinafter referred to comprehensivelyas a-Si(H,X)), said photoconductive member being prepared by designingso as to have a specific structure as hereinafter described, not onlyexhibits practically extremely excellent characteristics but alsosurpass the photoconductive members of the prior art in substantiallyall respects, especially having markedly excellent characteristics as aphotoconductive member for electrophotography and also excellentabsorption spectrum characteristics on the longer wavelength side.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide aphotoconductive member having electrical, optical and photoconductivecharacteristics which are constantly stable and all-environment typewith virtually no dependence on the environments under use, which memberis markedly excellent in photosensitive characteristics on the longerwavelength side and light fatigue resistance, and also excellent indurability without causing deterioration phenomenon when usedrepeatedly, exhibiting no or substantially no residual potentialobserved.

Another object of the present invention is to provide a photoconductivemember which is high in photosensitivity throughout the whole visiblelight region, particularly excellent in matching to a semiconductorlaser and also rapid in response to light.

Another object of the present invention is to provide a photoconductivemember which is excellent in adhesion between a substrate and a layerprovided on the substrate or between respective laminated layers, stablewith closeness of structural arrangement and high in layer quality.

Still another object of the present invention is to provide aphotoconductive member having sufficiently an ability to retain chargesduring charging treatment for formation of electrostatic images, whenapplied as a member for formation of an electrophotographic image andhaving excellent electrophotographic characteristics which is notsubstantially lowered even in a humid atmosphere, for which ordinaryelectrophotographic methods can very effectively be applied.

Further, still another object of the present invention is to provide aphotoconductive member for electrophotography, which can easily providean image of high quality which is high in density, clear in halftone,high in resolution and free from "unfocused" image.

Still another object of the present invention is to provide aphotoconductive member having high photosensitivity and high SN ratiocharacteristic, and a good electrical contact with the substrate.

According to the present invention, there is provided a photoconductivemember comprising a substrate for photoconductive member and a lightreceiving layer provided on said substrate having a layer constitutionin which a first layer region (G) comprising an amorphous materialcontaining germanium atoms and a second layer region (S) exhibitingphotoconductivity comprising an amorphous material containing siliconatoms are successively provided from the substrate side, said lightreceiving layer containing nitrogen atoms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 11 each shows a schematic sectional view forillustration of the layer constitution of a preferred embodiment of thephotoconductive member according to the present invention;

FIGS. 2 to 10 each shows a schematic illustration of the depth profileof nitrogen atoms in the layer region (N); and

FIG. 12 is a schematic illustration of the device used for preparationof the photoconductive members of the present invention in Examples.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, the photoconductive members according tothe present invention are to be described in detail below.

FIG. 1 shows a schematic sectional view for illustration of the layerconstitution of a first embodiment of the photoconductive member of thisinvention.

The photoconductive member 100 as shown in FIG. 1 is constituted of alight receiving layer 102 formed on a substrate 101 for photoconductivemember, said light receiving layer 102 having a free surface 105 on oneend surface.

The light receiving layer 102 has a layer structure constituted of afirst layer region (G) 103 consisting of germanium atoms and, ifdesired, at least one of silicon atoms (Si), hydrogen atoms (H) andhalogen atoms (X) (hereinafter abbreviated as "a-Ge(Si,H,X)" and asecond layer region (S) 104 having photoconductivity consisting ofa-Si(H,X) laminated successively from the substrate side 101.

In the case when germanium atoms are contained in the first layer region(G) 103 together with other atoms, germanium atoms are contained in saidfirst layer region (G) 103 in such a distribution that they aredistributed continuously and uniformly both in the layer thicknessdirection of said first layer region (G) 103 and in the interplanardirection in parallel to the surface of the substrate 101.

In the present invention, in the second layer region (S) provided on thefirst layer region (G), no germanium atom is contained, and by formingthe light receiving layer to such a layer structure, it is possible togive a photoconductive member which is excellent in photosensitivity tothe light over the entire wavelength region from relatively shorterwavelength to relatively longer wavelength including visible lightregion.

Also, since the distribution of germanium atoms in the first layerregion (G) is such that germanium atoms are distributed continuouslyover all the layer region, affinity between the first layer region (G)and the second layer region (S) is excellent, and the light on thelonger wavelength side which cannot substantially be absorbed by thesecond layer region (S) can be absorbed in the first layer region (G)substantially completely, when employing a semiconductor laser, wherebyinterference by reflection from the substrate surface can be prevented.

Also, in the photoconductive member of the present invention, whensilicon atoms are contained in the first layer region (G) the respectivelight receiving materials constituting the first layer region (G) andthe second layer region (S) have the common constituent of siliconatoms, and therefore chemical stability can be sufficiently ensured atthe laminated interface.

In the present invention, the content of germanium atoms in the firstlayer region (G) containing germanium atoms, which may suitably bedetermined as desired so as to achieve effectively the objects of thepresent invention, may preferably be 1 to 10×10⁵ atomic ppm, morepreferably 100 to 9.5×10⁵ atomic ppm, most preferably 500 to 8×10⁵atomic ppm based on the sum of germanium atoms and silicon atoms.

In the photoconductive member of the present invention, the layerthickness of the first layer region (G) and the thickness of the secondlayer region (S) are one of important factors for accomplishingeffectively the object of the present invention and therefore sufficientcare should be paid in designing of the photoconductive member so thatdesirable characteristics may be imparted to the photoconductive memberformed.

In the present invention, the layer thickness T_(B) of the first layerregion (G) may preferably be 30 Å to 50μ, more preferably 40 Å to 40μ,most preferably 50 Å to 30μ.

On the other hand, the layer thickness T of the second layer region (S)may be preferably 0.5 to 90μ, more preferably 1 to 80μ, most preferably2 to 50μ.

The sum of the layer thickness T_(B) of the first layer region (G) andthe layer thickness T of the second layer region (S), namely (T_(B) +T)may be suitably determined as desired in designing of the layers of thephotoconductive member, based on the mutual organic relationship betweenthe characteristics required for both layer regions and thecharacteristics required for the whole light receiving layer.

In the photoconductive member of the present invention, the numericalrange for the above (T_(B) +T) may preferably be from 1 to 100μ, morepreferably 1 to 80μ, most preferably 2 to 50μ.

In a more preferred embodiment of the present invention, it is preferredto select the numerical values for respective thicknesses T_(B) and T asmentioned above so that the relation of T_(B) /T≦1 may be satisfied.

In selection of the numerical values for the thicknesses T_(B) and T inthe above case, the values of T_(B) and T should preferably bedetermined so that the relation T_(B) /T≦0.9, most preferably, T_(B)/T≦0.8, may be satisfied.

In the present invention, when the content of germanium atoms in thefirst layer region (G) is 1×10⁵ atomic ppm or more, based on the sum ofgermanium atoms and silicon atoms the layer thickness T_(B) of the firstlayer region (G) should desirably be made as thin as possible,preferably 30μ or less, more preferably 25μ or less, most preferably 20μor less.

In the photoconductive member of the present invention, for the purposeof improvements to higher photosensitivity, higher dark resistance and,further, improvement of adhesion between the substrate and the lightreceiving layer, nitrogen atoms are contained in the light receivinglayer. The nitrogen atoms contained in the light receiving layer may becontained either evenly throughout the whole layer region of the lightreceiving layer or locally only in a part of the layer region of thelight receiving layer.

Nitrogen atoms may be distributed in such a state that the content C(N)may be either uniform or ununiform in the layer thickness direction inthe light receiving layer.

In the present invention, the layer region (N) containing nitrogen atomsprovided in the light receiving layer is provided so as to occupy thewhole layer region of the light receiving layer when it is intended toimprove primarily photosensitivity and dark resistance. On the otherhand, when the main object is to strengthen adhesion between thesubstrate and the light receiving layer, it is provided so as to occupythe end portion layer region (E) on the substrate side of the lightreceiving layer.

In the former case, the content of nitrogen atoms to be contained in thelayer region (N) is made relatively smaller in order to maintain highphotosensitivity, while in the latter case, it should desirably be maderelatively larger in order to ensure strengthening of adhesion with thesubstrate.

For the purpose of accomplishing simultaneously both of the former andthe latter cases, nitrogen atoms may be distributed at relatively highercontent on the substrate side and at relatively lower content on thefree surface side of the light receiving layer, or alternatively, theremay be formed a distribution of nitrogen atoms such that nitrogen atomsare not positively contained in the surface layer region on the freesurface side of the light receiving layer.

In the present invention, the content of nitrogen atoms to be containedin the layer region (N) provided in the light receiving layer may besuitably selected depending on the characteristics required for thelayer region (N) per se or, when said layer region (N) is provided indirect contact with the substrate, depending on the organic relationshipsuch the relation with the characteristics at the contacted interfacewith said substrate and others.

When another layer region is to be provided in direct contact with saidlayer region (N), the content of nitrogen atoms may be suitably selectedalso with considerations about the characteristics of said another layerregion and the relation with the characteristics of the contactedinterface with said another layer region.

The content of nitrogen atoms in the layer region (N), which maysuitably be determined as desired depending on the characteristicsrequired for the photoconductive member to be formed, may be preferably0.001 to 50 atomic %, more preferably 0.002 to 40 atomic %, mostpreferably 0.003 to 30 atomic %.

In the present invention, when the layer region (N) comprises the wholeregion of the light receiving layer or when, although it does notcomprises the whole layer region, the layer thickness (T_(N)) of thelayer region (N) is sufficiently large relative to the layer thickness Tof the light receiving layer, the upper limit of the content of nitrogenatoms in the layer region (N) should desirably be sufficiently smallerthan the aforesaid value.

In the case of the present invention, in such a case when the ratio ofthe layer thickness (T_(N)) of the layer region (N) relative to thelayer thickness T of the light receiving layer is 2/5 or higher, theupper limit of the content of nitrogen atoms in the layer region (N) maypreferably be 30 atomic % or less, more preferably 20 atomic % or less,most preferably 10 atomic % or less.

FIGS. 2 through 10 show typical examples of distribution in thedirection of layer thickness of nitrogen atoms contained in the layerregion (N) of the photoconductive member in the present invention.

In FIGS. 2 through 10, the abscissa indicates the content C(N) ofnitrogen atoms and the ordinate the layer thickness of the layer region(N), t_(B) showing the position of the end surface of the layer region(N) on the substrate side and t_(T) the position of the end surface ofthe layer region (N) on the side opposite to the substrate side. Thatis, layer formation of the layer region (N) containing nitrogen atomsproceeds from the t_(B) side toward the t_(T) side.

In FIG. 2, there is shown a first typical embodiment of the depthprofile of nitrogen atoms in the layer thickness direction contained inthe layer region (N).

In the embodiment as shown in FIG. 2, from the interface position t_(B)at which the surface of the substrate, on which the layer region (N)containing nitrogen atoms is to be formed, is contacted with the surfaceof said layer region (N) to the position t₁, nitrogen atoms arecontained in the layer region (N) formed, while the content C(N) ofnitrogen atoms taking a constant value of C₁, the content beinggradually decreased from the content C₂ continuously from the positiont₁ to the interface position t_(T). At the interface position t_(T), thecontent C(N) of nitrogen atoms is made C₃.

In the embodiment shown in FIG. 3, the content C(N) of nitrogen atomscontained is decreased gradually and continuously from the positiont_(B) to the position t_(T) from the content C₄ until it becomes thecontent C₅ at the position t_(T).

In case of FIG. 4, the content C(N) of nitrogen atoms is made constantas C₆ from the position t_(B) to t₂, gradually decreased continuouslyfrom the position t₂ to the position t_(T), and the content C(N) is madesubstantially zero at the position t_(T) (substantially zero hereinmeans the content less than the detectable limit).

In case of FIG. 5, the content C(N) of nitrogen atoms are decreasedgradually and continuously from the position t_(B) to the position t_(T)from the content C₈, until it is made substantially zero at the positiont_(T).

In the embodiment shown in FIG. 6, the content C(N) of nitrogen atoms isconstantly C₉ between the position t_(B) and the position t₃, and it ismade C₁₀ at the position t_(T). Between the position t₃ and the positiont_(T), the content is reduced as a first order function from theposition t₃ to the position t_(T).

In the embodiment shown in FIG. 7, there is formed a depth profile suchthat the content C(N) takes a constant value of C₁₁ from the positiont_(B) to the position t₄, and is decreased as a first order functionfrom the content C₁₂ to the content C₁₃ from the position t₄ to theposition t_(T).

In the embodiment shown in FIG. 8, the content C(N) of nitrogen atoms isdecreased as a first order function from the content C₁₄ to zero fromthe position t_(B) to the position t_(T).

In FIG. 9, there is shown an embodiment, where the content C(N) ofnitrogen atoms is decreased as a first order function from the contentC₁₅ to C₁₆ from the position t_(B) to t₅ and made constantly at thecontent C₁₆ between the position t₅ and t_(T).

In the embodiment shown in FIG. 10, the content C(N) of nitrogen atomsis at the content C₁₇ at the position t_(B), which content C₁₇ isinitially decreased gradually and abruptly near the position t₆ to theposition t₆, until it is made the content C₁₈ at the position t₆.

Between the position t₆ and the position t₇, the content C(N) isinitially decreased abruptly and thereafter gradually, until it is madethe content C₁₉ at the position t₇. Between the position t₇ and theposition t₈, the content is decreased very gradually to the content C₂₀at the position t₈. Between the position t₈ and the position t_(T), thecontent is decreased along the curve having a shape as shown in theFigure from the content C₂₀ to substantially zero.

As described above about some typical examples of depth profiles ofnitrogen atoms contained in the layer region (N) in the direction of thelayer thickness by referring to FIGS. 2 through 10, in the presentinvention, the layer region (N) is provided desirably in a depth profileso as to have a portion enriched in content C(N) of nitrogen atoms onthe substrate side and a portion depleted in content C(N) of nitrogenatoms to considerably lower than that of the substrate side on theinterface t_(T) side.

In the present invention, the layer region (N) containing nitrogen atomsfor constituting the light receiving layer may preferably be provided soas to have a localized region (B) containing nitrogen atoms at arelatively higher content on the substrate side as described above, andin this case adhesion between the substrate and the light receivinglayer can be further improved.

The localized region (B), as explained in terms of the symbols shown inFIGS. 2 to 10, may be desirably provided within 5μ from the interfaceposition t_(B).

In the present invention, the above localized region (B) may be made tobe identical with the whole layer region (L_(T)) up to the depth of 5μthickness from the interface position t_(B), or alternatively a part ofthe layer region (L_(T)).

It may suitably be determined depending on the characteristics requiredfor the light receiving layer to be formed, whether the localized region(B) is made a part or whole of the layer region (L_(T)).

The localized region (B) may preferably formed according to such a layerformation that the maximum Cmax of the content C(N) of nitrogen atoms ina distribution in the layer thickness direction may preferably be 500atomic ppm or more, more preferably 800 atomic ppm or more, mostpreferably 1000 atomic ppm or more.

That is, according to the present invention, the layer region (N)containing nitrogen atoms is formed so that the maximum value Cmax ofthe depth profile may exist within a layer thickness of 5μ from thesubstrate side (the layer region within 5μ thickness from t_(B)).

In the present invention, illustrative of halogen atoms (X), which mayoptionally be incorporated in the first layer region (G) and the secondlayer region (S) constituting the light receiving layer, are fluorine,chlorine, bromine and iodine, particularly preferably fluorine andchlorine.

In the present invention, formation of the first layer region (G)constituted of a-Ge(Si,H,X) may be conducted according to the vacuumdeposition method utilizing discharging phenomenon, such as glowdischarge method, sputtering method or ionplating method. For example,for formation of the first layer region (G) constituted of a-Ge(Si,H,X)according to the glow discharge method, the basic procedure comprisesintroducing a starting gas for Ge supply capable of supplying germaniumatoms (Ge) optionally together with a starting gas for Si supply capableof supplying silicon atoms (Si), and a starting gas for introduction ofhydrogen atoms (H) and/or a starting gas for introduction of halogenatoms (X) into a deposition chamber which can be internally brought to areduced pressure, and exciting glow discharge in said depositionchamber, thereby effecting layer formation on the surface of a substrateplaced at a predetermined position. For distributing ununiformly thegermanium atoms in the first layer region (G), a layer consisting ofa-Ge(Si,H,X) may be formed while controlling the depth profile ofgermanium atoms according to a desired change rate curve. Alternatively,for formation according to the sputtering method, when carrying outsputtering by use of a target constituted of Si or two sheets of targetsof said target and a target constituted of Ge, or a target of a mixtureof Si and Ge in an atmosphere of an inert gas such as Ar, He, etc. or agas mixture based on these gases, a starting gas for Ge supplyoptionally diluted with He, Ar, etc. and optionally together with, ifdesired, a gas for introduction of hydrogen atoms (H) and/or a gas forintroduction of halogen atoms (X) may be introduced into a depositionchamber for sputtering, thereby forming a plasma atmosphere of a desiredgas, and sputtering of the aforesaid target may be effected, whilecontrolling the gas flow rates of the starting gas for supply of Geaccording to a desired change rate curve.

In the case of the ion-plating method, for example, a vaporizing sourcesuch as a polycrystalline silicon or a single crystalline silicon and apolycrystalline germanium or a single crystalline germanium may beplaced as vaporizing source in an evaporating boat, and the vaporizingsource is heated by the resistance heating method or the electron beammethod (EB method) to be vaporized, and the flying vaporized product ispermitted to pass through a desired gas plasma atmosphere, otherwisefollowing the same procedure as in the case of sputtering.

The starting gas for supplying Si to be used in the present inventionmay include gaseous or gasifiable hydrogenated silicons (silanes) suchas SiH₄, Si₂ H₆, Si₃ H₈, Si₄ H₁₀ and others as effective materials. Inparticular, SiH₄ and Si₂ H₆ are preferred with respect to easy handlingduring layer formation and efficiency for supplying Si.

As the substances which can be starting gases for Ge supply, there maybe effectively employed gaseous or gasifiable hydrogenated germaniumsuch as GeH₄, Ge₂ H₆, Ge₃ H₈, Ge₄ H₁₀, Ge₅ H₁₂, Ge₆ H₁₄, Ge₇ H₁₆, Ge₈H₁₈, Ge₉ H₂₀, etc. In particular, GeH₄, Ge₂ H₆ and Ge₃ H₈ are preferredwith respect to easy handling during layer formation and efficiency forsupplying Ge.

Effective starting gases for introduction of halogen atoms to be used inthe present invention may include a large number of halogenic compounds,as exemplified preferably by gaseous or gasifiable halogenic compoundssuch as halogenic gases, halides, interhalogen compounds, silanederivatives substituted with halogens, and the like.

Further, there may also be included gaseous or gasifiable siliconcompounds containing halogen atoms constituted of silicon atoms andhalogen atoms as constituent elements as effective ones in the presentinvention.

Typical examples of halogen compounds preferably used in the presentinvention may include halogen gases such as of fluorine, chlorine,bromine or iodine, interhalogen compounds such as BrF, ClF, ClF₃, BrF₅,BrF₃, IF₃, IF₇, ICl, IBr, etc.

As the silicon compounds containing halogen atoms, namely so calledsilane derivatives substituted with halogens, there may preferably beemployed silicon halides such as SiF₄, Si₂ F₆, SiCl₄, SiBr₄ and thelike.

When the characteristic photoconductive member of the present inventionis formed according to the glow discharge method by employment of such asilicon compound containing halogen atoms, it is possible to form thefirst layer region (G) comprising a-SiGe containing halogen atoms on adesired substrate without use of a hydrogenated silicon gas as thestarting gas capable of supplying Si together with the starting gas forGe supply.

In the case of forming the first layer region (G) containing halogenatoms according to the glow discharge method, the basic procedurecomprises introducing, for example, a silicon halide as the starting gasfor Si supply, a hydrogenated germanium as the starting gas for Gesupply and a gas such as Ar, H₂, He, etc. at a predetermined mixingratio into the deposition chamber for formation of the first layerregion (G) and exciting glow discharge to form a plasma atmosphere ofthese gases, whereby the first layer region (G) can be formed on adesired substrate. In order to control the ratio of hydrogen atomsincorporated more easily, hydrogen gas or a gas of a silicon compoundcontaining hydrogen atoms may also be mixed with these gases in adesired amount to form the layer.

Also, each gas is not restricted to a single species, but multiplespecies may be available at any desired ratio.

In either case of the sputtering method and the ion-plating method,introduction of halogen atoms into the layer formed may be performed byintroducing the gas of the above halogen compound or the above siliconcompound containing halogen atoms into a deposition chamber and forminga plasma atmosphere of said gas.

On the other hand, for introduction of hydrogen atoms, a starting gasfor introduction of hydrogen atoms, for example, H₂ or gases such assilanes and/or hydrogenated germanium as mentioned above, may beintroduced into a deposition chamber for sputtering, followed byformation of the plasma atmosphere of said gases.

In the present invention, as the starting gas for introduction ofhalogen atoms, the halides or halo-containing silicon compounds asmentioned above can effectively be used. Otherwise, it is also possibleto use effectively as the starting material for formation of the firstlayer region (G) gaseous or gasifiable substances, including halidescontaining hydrogen atom as one of the constituents, e.g. hydrogenhalide such as HF, HCl, HBr, Hi, etc.; halo-substituted hydrogenatedsilicon such as SiH₂ F₂, SiH₂ I₂, SiH₂ Cl₂, SiHCl₃, SiH₂ Br₂, SiHBr₃,etc.; hydrogenated germanium halides such as GeHF₃, GeH₂ F₂, GeH₃ F,GeHCl₃, GeH₂ Cl₂, GeH₃ Cl, GeHBr₃, GeH₂ Br₂, GeH₃ Br, GeHI₃, GeH₂ I₂,GeH₃ I, etc.; germanium halides such as GeF₄, GeCl₄, GeBr₄, GeI₄, GeF₂,GeCl₂, GeBr₂, GeI₂, etc.

Among these substances, halides containing hydrogen atoms can preferablybe used as the starting material for introduction of halogen atoms,because hydrogen atoms, which are very effective for controllingelectrical or photoelectric characteristics, can be introduced into thelayer simultaneously with introduction of halogen atoms during formationof the first layer region (G).

For introducing hydrogen atoms structurally into the first layer region(G), other than those as mentioned above, H₂ or a hydrogenated siliconsuch as SiH₄, Si₂ H₆, Si₃ H₈, Si₄ H₁₀, etc. together with germanium or agermanium compound for supplying Ge, or a hydrogenated germanium such asGeH₄, Ge₂ H₆, Ge₃ H₈, Ge₄ H₁₀, Ge₅ H₁₂, Ge₆ H₁₄, Ge₇ H₁₆, Ge₈ H₁₈, Ge₉H₂₀, etc. together with silicon or a silicon compound for supplying Sican be permitted to co-exist in a deposition chamber, followed byexcitation of discharging.

According to a preferred embodiment of the present invention, the amountof hydrogen atoms (H) or the amount of halogen atoms (X) or the sum ofthe amounts of hydrogen atoms and halogen atoms (H+X) to be contained inthe first layer region (G) constituting the photoconductive layer to beformed should preferably be 0.01 to 40 atomic %, more preferably 0.05 to30 atomic %, most preferably 0.1 to 25 atomic %.

For controlling the amount of hydrogen atoms (H) and/or halogen atoms(X) to be contained in the first layer region (G), for example, thesubstrate temperature and/or the amount of the starting materials usedfor incorporation of hydrogen atoms (H) or halogen atoms (X) to beintroduced into the deposition device system, discharging power, etc.may be controlled.

In the present invention, for formation of the second layer region (S)constituted of a-Si(H,X), the starting materials (I) for formation ofthe first layer region (G), from which the starting material for thestarting gas for supplying Ge is omitted, are used as the startingmaterials (II) for formation of the second layer region (S), and layerformation can be effected following the same procedure and conditions asin formation of the first layer region (G).

More specifically, in the present invention, formation of the secondlayer region (S) constituted of a-Si(H,X) may be carried out accordingto the vacuum deposition method utilizing discharging phenomenon such asthe glow discharge method, the sputtering method or the ion-platingmethod. For example, for formation of the second layer region (S)constituted of a-Si(H,X), the basic procedure comprises introducing astarting gas for Si supply capable of supplying silicon atoms asdescribed above, optionally together with starting gases forintroduction of hydrogen atoms (H) and/or halogen atoms (X), into adeposition chamber which can be brought internally to a reduced pressureand exciting glow discharge in said deposition chamber, thereby forminga layer comprising a-Si(H,X) on a desired substrate placed at apredetermined position. Alternatively, for formation according to thesputtering method, gases for introduction of hydrogen atoms (H) and/orhalogen atoms (X) may be introduced into a deposition chamber wheneffecting sputtering of a target constituted of Si in an inert gas suchas Ar, He, etc. or a gas mixture based on these gases.

In the photoconductive member of the present invention, by incorporatinga substance (C) for controlling conductivity in the second layer region(S) containing no germanium atom provided on the first layer region (G)containing germanium atoms, the conductivities of said layer region (S)can be controlled freely as desired.

As a substance (C) for controlling conductivity characteristics, theremay be mentioned so called impurities in the field of semiconductors. Inthe present invention, there may be included p-type impurities givingp-type conductivity characteristics and n-type impurities giving n-typeconductivity characteristics to a-Si(H,X) constituting the second layerregion (S) formed.

More specifically, there may be mentioned as p-type impurities atomsbelonging to the group III of the periodic table (Group III atoms), suchas B (boron), Al (aluminum), Ga (gallium), In (indium), Tl (thallium),etc., particularly preferably B and Ga.

As n-type impurities, there may be included the atoms belonging to thegroup V of the periodic table (Group V atoms), such as P (phosphorus),As (arsenic), Sb (antimony), Bi (bismuth), etc., particularly preferablyP and As.

In the present invention, the content of the substance (C) forcontrolling conductivity in the second layer region (S) may be suitablybe selected depending on the conductivity required for said layer region(S), or the relationships with characteristics of other layer regionsprovided in direct contact with said layer region (S) or thecharacteristics at the contacted interface with said other layerregions.

In the present invention, the content of the substance (C) forcontrolling conductivity contained in the second layer region (S) shouldpreferably be 0.001 to 1000 atomic ppm, more preferably 0.005 to 500atomic ppm, most preferably 0.1-200 atomic ppm.

For incorporating a substance (C) for controlling conductivity such asthe group III atoms or the group V atoms structurally into the secondlayer region (S), a starting material for introduction of the group IIIatoms or a starting material for introduction of the group V atoms maybe introduced under gaseous state into a deposition chamber togetherwith the starting materials for formation of the second layer regionduring layer formation. As the starting material which can be used forintroduction of the group III atoms, it is desirable to use those whichare gaseous at room temperature under atmospheric pressure or canreadily be gasified at least under layer forming conditions. Typicalexamples of such starting materials for introduction of the group IIIatoms, there may be included as the compounds for introduction of boronatoms boron hydrides such as B₂ H₆, B₄ H₁₀, B₅ H₉, B₅ H₁₁, B₆ H₁₀, B₆H₁₂, B₆ H₁₄, etc. and boron halides such as BF₃, BCl₃, BBr₃, etc.Otherwise, it is also possible to use AlCl₃, GaCl₃, Ga(CH₃)₃, InCl₃,TlCl₃ and the like.

The starting materials which can effectively be used in the presentinvention for introduction of the group V atoms may include, forintroduction of phosphorus atoms, phosphorus hydride such as PH₃, P₂ H₄,etc., phosphorus halides such as PH₄ I, PF₃, PF₅, PCl₃, PCl₅, PBr₃,PBr₅, PI₃ and the like. Otherwise, it is also possible to utilize AsH₃,AsF₃, AsCl₃, AsBr₃, AsF₅, SbH₃, SbF₃, SbF₅, SbCl₃, SbCl₅, BiH₃, BiCl₃,BiBr₃ and the like effectively as the starting material for introductionof the group V atoms.

In the present invention, for provision of the layer region (N)containing nitrogen atoms in the light receiving layer, a startingmaterial for introduction of nitrogen atoms may be used together withthe starting material for formation of the light receiving layer asmentioned above during formation of the light receiving layer and may beincorporated in the layer formed while controlling their amounts.

When the glow discharge method is to be employed for formation of thelayer region (N), the starting material as the starting gas forformation of the layer region (N) may be constituted by adding astarting material for introduction of nitrogen atoms to the startingmaterial selected as desired from those for formation of the lightreceiving layer as mentioned above. As such a starting material forintroduction of nitrogen atoms, there may be employed most of gaseous orgasifiable substances containing at least nitrogen atoms as constituentatoms.

For example, there may be employed a mixture of a starting gascontaining silicon atoms (Si) as constituent atoms, a starting gascontaining nitrogen atoms (N) as constituent atoms and optionally astarting gas containing hydrogen atoms (H) and/or halogen atoms (X) asconstituent atoms at a desired mixing ratio; a mixture of a starting gascontaining silicon atoms (Si) as constituent atoms and a starting gascontaining nitrogen atoms and hydrogen atoms as constituent atoms alsoat a desired mixing ratio.

Alternatively, there may also be employed a mixture of a starting gascontaining silicon atoms (Si) and hydrogen atoms (H) as constituentatoms and a starting gas containing nitrogen atoms (N) as constituentatoms.

The starting material effectively used as the starting gas forintroduction of nitrogen atoms (N) to be used during formation of thelayer region (N), it is possible to use compounds containing N asconstituent atom or compounds containing N and H as constituent atoms,such as gaseous or gasifiable nitrogen compounds, nitrides and azides,including for example, nitrogen (N₂), ammonia (NH₃), hydrazine (H₂NNH₂), hydrogen azide (HN₃), ammonium azide (NH₄ N₃) and so on.Alternatively, for the advantage of introducing halogen atoms (X) inaddition to nitrogen atoms (N), there may be also employed nitrogenhalide compounds such as nitrogen trifluoride (F₃ N), dinitrogentetrafluoride (F₄ N₂) and the like.

In the present invention, for further promoting the effect obtained bynitrogen atoms, it is possible to incorporate oxygen atoms in additionto nitrogen atoms in the layer region (N). The starting gas forintroduction of oxygen atoms in the layer region may include, forexample, oxygen (O₂), ozone (O₃), nitrogen monoxide (NO), nitrogendioxide (NO₂), dinitrogen monoxide (N₂ O), dinitrogen trioxide (N₂ O₃),dinitrogen tetraoxide (N₂ O₄), dinitrogen pentaoxide (N₂ O₅), nitrogentrioxide (NO₃), and lower siloxanes containing silicon atoms (Si),oxygen atoms (O) and hydrogen atoms (H) as constituent atoms such asdisiloxane (H₃ SiOSiH₃), trisiloxane (H₃ SiOSiH₂ OSiH₃), and the like.

For formation of the layer region (N) containing nitrogen atomsaccording to the sputtering method, a single crystalline orpolycrystalline Si wafer or Si₃ N₄ wafer or a wafer containing Si andSi₃ N₄ mixed therein may be employed and sputtering of these wafers maybe conducted in various gas atmospheres.

For example, when Si wafer is employed as the target, a starting gas forintroduction of nitrogen atoms optionally together with a starting gasfor introduction of hydrogen atoms and/or halogen atoms, which mayoptionally be diluted with a diluting gas, may be introduced into adeposition chamber for sputtering to form gas plasma of these gases, inwhich sputtering of the aforesaid Si wafer may be effected.

Alternatively, by use of separate tragets of Si and Si₃ N₄ or one sheetof a target containing Si and Si₃ N₄ mixed therein, sputtering may beeffected in an atmosphere of a diluting gas as a gas for sputtering orin a gas atmosphere containing at least hydrogen atoms (H) and/orhalogen atoms (X) as constituent atoms. As the starting gas forintroduction of nitrogen atoms, there may be employed the starting gasesshown as examples in the glow discharge method previously described alsoas effective gases in case of sputtering.

In the present invention, when providing a layer region (N) containingnitrogen atoms during formation of the light receiving layer, formationof the layer region (N) having a desired distribution state in thedirection of layer thickness (depth profile) by varying the content C(N)of nitrogen atoms contained in said layer region (N) may be conducted incase of glow discharge by introducing a starting gas for introduction ofnitrogen atoms of which the content C(N) is to be varied into adeposition chamber, while varying suitably its gas flow rate accordingto a desired change rate curve. For example, by the manual method or anyother method conventionally used such as an externally driven motor,etc., the opening of certain needle valve provided in the course of thegas flow channel system may be gradually varied. During this procedure,the rate of variation is not necessarily required to be linear, but theflow rate may be controlled according to a variation rate curvepreviously designed by means of, for example, a micro-computer to give adesired content curve.

In case when the layer region (N) is formed by the sputtering method,formation of a desired depth profile of nitrogen atoms in the directionof layer thickness by varying the content C(N) of nitrogen atoms in thedirection of layer thickness may be performed first similarly as in caseof the glow discharge method by employing a starting material forintroduction of nitrogen atoms under gaseous state and varying suitablyas desired the gas flow rate of said gas when introduced into thedeposition chamber.

Secondly, formation of such a depth profile can also be achieved bypreviously changing the composition of a target for sputtering. Forexample, when a target comprising a mixture of Si and Si₃ N₄ is to beused, the mixing ratio of Si to Si₃ N₄ may be varied in the direction oflayer thickness of the target.

In the present invention, the amount of hydrogen atoms (H) or the amountof halogen atoms (X) or the sum of the amounts of hydrogen atoms andhalogen atoms (H+X) to be contained in the second layer region (S)constituting the light receiving layer to be formed should preferably be1 to 40 atomic %, more preferably 5 to 30 atomic %, most preferably 5 to25 atomic %.

The substrate to be used in the present invention may be eitherelectroconductive material or insulating material. As theelectroconductive material, there may be mentioned metals such as NiCr,stainless steel, Al, Cr, Mo, Au, Nb, Ta, V, Ti, Pt, Pd etc. or alloysthereof.

As the insulating material, there may conventionally be used films orsheets of synthetic resins, including polyester, polyethylene,polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride,polyvinylidene chloride, polystyrene, polyamide, etc., glasses,ceramics, papers and so on. These insulating substrates shouldpreferably have at least one surface subjected to electroconductivetreatment, and it is desirable to provide other layers on the side atwhich said electroconductive treatment has been applied.

For example, electroconductive treatment of a glass can be effected byproviding a thin film of NiCr, Al, Cr, Mo,Au, Ir, Nb, Ta, V, Ti, Pt, Pd,In₂ O₃, SnO₂, ITO (In₂ O₃ +SnO₂) thereon. Alternatively, a syntheticresin film such as polyester film can be subjected to theelectroconductive treatment on its surface by vacuum vapor deposition,electron-beam deposition or sputtering of a metal such as NiCr, Al, Ag,Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Ti, Pt, etc. or by laminatingtreatment with said metal, thereby imparting electroconductivity to thesurface. The substrate may be shaped in any form such as cylinders,belts, plates or others, and its form may be determined as desired. Forexample, when the photoconductive member 100 in FIG. 1 is to be used asan image forming member for electrophotography, it may desirably beformed into an endless belt or a cylinder for use in continuous highspeed copying. The substrate may have a thickness, which is convenientlydetermined so that a photoconductive member as desired may be formed.When the photoconductive member is required to have a flexibility, thesubstrate is made as thin as possible, so far as the function of asubstrate can be sufficiently exhibited. However, in such a case, thethickness is preferably 10μ or more from the points of fabrication andhandling of the substrate as well as its mechanical strength.

FIG. 11 shows a schematic illustration for explanation of the layerstructure of the second embodiment of the photoconductive member of thepresent invention.

The photoconductive member 1100 shown in FIG. 11 has a substrate forphotoconductive member 1101, and a first layer (I) 1102 and a secondlayer (II) 1103 provided on said substrate 1101, said second layer (II)1103 having a free surface 1106 on one end surface.

The photoconductive member 1100 shown in FIG. 11 has the sameconstitution as the photoconductive member 100 shown in FIG. 1 exceptfor having the second layer (II) 1103 laminated on the first layer (I)1102 which corresponds to the light receiving layer 102.

That is, the substrate 1101, the first layer region (G) 1104, and thesecond layer region (S) 1105 correspond to the substrate 101, the firstlayer region (G) 103 and the second layer region (S) 104, respectively,and all the descriptions about these may be applicable similarly.

In the photoconductive member 100 shown in FIG. 1, the layer region (N)containing nitrogen atoms is provided in the light receiving layer 102as described in detail above. This point is also applicable similarly tothe photoconductive member 1101 shown in FIG. 11.

The above amorphous material constituting the second layer (II) mayinclude an amorphous material containing silicon atoms (Si) and carbonatoms (C), optionally together with hydrogen atoms (H) and/or halogenatoms (X) (hereinafter written as "a-(Si_(x) C_(1-x))y(H,X)1-y", wherein0<x, y<1) and an amorphous material containing silicon atoms (Si) andoxygen atoms (O), optionally together with hydrogen atoms (H) and/orhalogen atoms (X) (hereinafter written as "a-(Si_(x) O_(1-x))y(H,X)1-y",wherein 0<x, y<1).

Thus, in the photoconductive member 1100 with the layer structure shownin FIG. 11, the respective amorphous materials constituting the firstlayer (I) 1102 and the second layer (II) 1103 have the commonconstituent of silicon atom, and therefore chemical stability issufficiently ensured at the laminated interface.

Formation of the second amorphous layer (II) constituted of theseamorphous materials may be performed according to the glow dischargemethod, the sputtering method, the ion-implantation method, theion-plating method, the electron beam method, etc. These preparationmethods may be suitably selected depending on various factors such asthe preparation conditions, the extent of the load for capitalinvestment for installations, the production scale, the desirablecharacteristics required for the photoconductive member to be prepared,etc. For the advantages of relatively easy control of the preparationconditions for preparing photoconductive members having desiredcharacteristics and easy introduction of carbon atoms and/or oxygenatoms, hydrogen atoms and/or halogen atoms with silicon atoms (Si) intothe second layer (II) to be prepared, there may preferably be employedthe glow discharge method or the sputtering method.

Further, in the present invention, the glow discharge method and thesputtering method may be used in combination in the same device systemto form the second layer (II).

For formation of the second layer (II) according to the glow dischargemethod, starting gases for formation of amorphous material constitutingthe second layer (II), which may optionally be mixed with a diluting gasat a predetermined mixing ratio, may be introduced into a depositionchamber for vacuum deposition in which a substrate is placed, and glowdischarge is excited in said deposition chamber to form the gasesintroduced into a gas plasma, thereby depositing amorphous material forformation of the second layer (II) on the first layer (I) already formedon the substrate.

In the present invention, as starting gases for formation of a-(Si_(x)C_(1-x))y(H,X)1-y, there may be employed most of substances containingat least one of silicon atoms (Si), carbon atoms (C), hydrogen atoms (H)and halogen atoms (X) as constituent atoms which are gaseous or gasifiedsubstances of readily gasifiable ones.

For example, it is possible to use a mixture of a starting gascontaining Si as constituent atom, a starting gas containing C asconstituent atom and optionally a starting gas containing H asconstituent atom and/or a starting gas containing X as constituent atomat a desired mixing ratio, or a mixture of a starting gas containing Sias constituent atom and a starting gas containing C and H as constituentatoms and/or a starting gas containing C and X as constituent atoms alsoat a desired ratio, or a mixture of a starting gas containing Si asconstituent atom and a starting gas containing three constituent atomsof Si, C and H or a starting gas containing three constituent atoms ofSi, C and X.

Alternatively, it is also possible to use a mixture of a starting gascontaining Si and H as constituent atoms with a starting gas containingC as constituent atom or a mixture of a starting gas containing Si and Xas constituent atoms and a starting gas containing C as constituentatom.

In the present invention, as starting gases for formation of a-(Si_(x)O_(1-x))y(H,X)1-y, there may be employed most of substances containingat least one of silicon atoms (Si), oxygen atoms (O), hydrogen atoms (H)and halogen atoms (X) as constituent atoms which are gaseous or gasifiedsubstances of readily gasifiable ones.

For example, it is possible to use a mixture of a starting gascontaining Si as constituent atom, a starting gas containing O asconstituent atom and optionally a starting gas containing H asconstituent atom and/or a starting gas containing X as constituent atomat a desired mixing ratio, or a mixture of a starting gas containing Sias constituent atom and a starting gas containing O and H as constituentatoms and/or a starting gas containing O and X as constituent atoms alsoat a desired ratio, or a mixture of a starting gas containing Si asconstituent atom and a starting gas containing three constituent atomsof Si, O and H or a starting gas containing three constituent atoms ofSi, O and X.

Alternatively, it is also possible to use a mixture of a starting gascontaining Si and H as constituent atoms with a starting gas containing0 as constituent atom or a mixture of a starting gas containing Si and Xas constituent atoms and a starting gas containing O as constituentatom.

In the present invention, suitable halogen atoms (X) contained in thesecond layer (II) are F, Cl, Br and I, particularly preferably F and Cl.

In the present invention, the starting gas which can be effectively usedfor formation of the second layer (II) may include those which aregaseous under conditions of room temperature and atmospheric pressure orcan be readily gasified.

Formation of the second layer (II) according to the sputtering methodmay be practiced as follows.

In the first place, when a target constituted of Si is subjected tosputtering in an atmosphere of an inert gas such as Ar, He, etc. or agas mixture based on these gases, a starting gas for introduction ofcarbon atoms (C) and/or a starting gas for introduction of oxygen atoms(O) may be introduced, optionally together with starting gases forintroduction of hydrogen atoms (H) and/or halogen atoms (X), into avacuum deposition chamber for carrying out sputtering.

In the second place, carbon atoms (C) and/or oxygen atoms (O) can beintroduced into the second layer (II) formed by the use of a targetconstituted of SiO₂ or graphite, or two sheets of a target constitutedof Si and a target constituted of SiO₂ and/or graphite or a targetconstituted of Si and SiO₂ and/or graphite. In this case, if thestarting gas for introduction of carbon atoms (C) and/or the startinggas for introduction of oxygen atoms (O) as mentioned above is used incombination, the amount of carbon atoms (C) and/or oxygen atoms (O) tobe incorporated in the second layer (II) can easily be controlled asdesired by controlling the flow rate thereof.

The amount of carbon atoms (C) and/or oxygen atoms (O) to beincorporated into the second layer (II) can be controlled as desired bycontrolling the flow rate of the starting gas for introduction of carbonatoms (C) and/or the starting gas for introduction of oxygen atoms (O),adjusting the ratio of carbon atoms (C) and/or oxygen atoms (O) in thetarget for introduction of carbon atoms and/or oxygen atoms duringpreparation of the target, or performing both of these.

The starting gas for supplying Si to be used in the present inventionmay include gaseous or gasifiable hydrogenated silicons (silanes) suchas SiH₄, Si₂ H₆, Si₃ H₈, Si₄ H₁₀ and others as effective materials. Inparticular, SiH₄ and Si₂ H₆ are preferred with respect to easy handlingduring layer formation and efficiency for supplying Si.

By the use of these starting materials, H can also be incorporatedtogether with Si in the second layer (II) formed by adequate choice ofthe layer forming conditions.

As the starting materials effectively used for supplying Si, in additionto the hydrogenated silicons as mentioned above, there may be includedsilicon compounds containing halogen atoms (X), namely the so calledsilane derivatives substituted with halogen atoms, including siliconhalogenide such as SiF₄, Si₂ F₆, SiCl₄, SiBr₄, SiCl₃ Br, SiCl₂ Br₂,SiClBr₃, SiCl₃ I, etc., as preferable ones.

Further, halides containing hydrogen atoms as one of the constituents,which are gaseous or gasifiable, such as halo-substituted hydrogenatedsilicon, including SiH₂ F₂, SiH₂ I₂, SiH₂ Cl₂, SiHCl₃, SiH₃ Br, SiH₂Br₂, SiHBr₃, etc. may also be mentioned as the effective startingmaterials for supplying Si for formation of the second layer (II).

Also, in the case of employing a silicon compound containing halogenatoms (X), X can be introduced together with Si in the second layer (II)formed by suitable choice of the layer forming conditions as mentionedabove.

Among the starting materials described above, silicon halogenidecompounds containing hydrogen atoms are used as preferable startingmaterial for introduction of halogen atoms (X) in the present inventionsince, during the formation of the second layer (II), hydrogen atoms(H), which are extremely effective for controlling electrical orphotoelectric characeristics, can be incorporated together with halogenatoms (X) into the layer.

Effective starting materials to be used as the starting gases forintroduction of halogen atoms (X) in formation of the second layer (II)in the present invention, there may be included, in addition to those asmentioned above, for example, halogen gases such as fluorine, chlorine,bromine and iodine; interhalogen compounds such as BrF, ClF, ClF₃, BrF₅,BrF₃, IF₃, IF₇, ICl, IBr, etc. and hydrogen halide such as HF, HCl, HBr,HI, etc.

The starting gas for introduction of carbon atoms (C) to be used information of the second layer (II) may include compounds containing Cand H as constituent atoms such as saturated hydrocarbons containing 1to 4 carbon atoms, ethylenic hydrocarbons having 2 to 4 carbon atoms,acetylenic hydrocarbons having 2 to 3 carbons atoms, etc.

More specifically, there may be included, as saturated hydrocarbons,methane (CH₄), ethane (C₂ H₆), propane (C₃ H₈), n-butane (n-C₄ H₁₀),pentane (C₅ H₁₂); as ethylenic hydrocarbons, ethylene (C₂ H₄), propylene(C₃ H₆), butene-1 (C₄ H₈), butene-2 (C₄ H₈), isobutylene (C₄ H₈),pentene (C₅ H₁₀); as acetylenic hydrocarbons, acetylene (C₂ H₂), methylacetylene (C₃ H₄), butyne (C₄ H₆).

Otherwise, it is also possible to use halosubstituted paraffinichydrocarbons such as CF₄, CCl₄, CBr₄, CHF₃, CH₂ F₂, CH₃ F, CH₃ Cl, CH₃Br, CH₃ I, C₂ H₅ Cl, etc.; fluorinated sulfur compounds such as SF₄,SF₆, etc.; silane derivatives, including alkyl silanes such as Si(CH₃)₄,Si(C₂ H₅)₄, etc. and halocontaining alkyl silanes such as SiCl(CH₃)₃,SiCl₂ (CH₃)₂, SiCl₃ CH₃, etc. as effective ones.

The starting materials for formation of the above second layer (II) maybe selected and employed as desired in formation of the second layer(II) so that silicon atoms, and carbon atoms and/or oxygen atoms,optionally together with hydrogen atoms and/or halogen atoms may becontained at a predetermined composition ratio in the second layer (II)to be formed.

For example, Si(CH₃)₄ as the material capable of incorporating easilysilicon atoms, carbon atoms and hydrogen atoms and forming a layerhaving desired characteristics and SiHCl₃, SiCl₄, SiH₂ Cl₂ or SiH₃ Cl asthe material for incorporating halogen atoms may be mixed at apredetermined mixing ratio and introduced under gaseous state into adevice for formation of a second layer (II), followed by excitation ofglow discharge, whereby there can be formed a second layer (II)comprising a-(Si_(x) C_(1-x))y(Cl+H)_(1-y).

The starting material effectively used as the starting gas forintroduction of oxygen atoms (O) to be used during formation of thesecond layer (II), it is possible to use compounds containing O asconstituent atom or compounds containing N and O as constituent atoms,such as oxygen (O₂), ozone (O₃), nitrogen monoxide (NO), nitrogendioxide (NO₂), dinitrogen monoxide (N₂ O), dinitrogen trioxide (N₂ O₃),dinitrogen tetraoxide (N₂ O₄), dinitrogen pentaoxide (N₂ O₅), nitrogentrioxide (NO₃), and lower siloxanes containing silicon atoms (Si),oxygen atoms (O) and hydrogen atoms (H) as constituent atoms such asdisiloxane (H₃ SiOSiH₃), trisiloxane (H₃ SiOSiH₂ OSiH₃), and the like.

In the present invention, as the diluting gas to be used in formation ofthe second layer (II) by the glow discharge method or the sputteringmethod, there may be included the so called rare gases such as He, Neand Ar as preferable ones.

The second layer (II) in the present invention should be carefullyformed so that the required characteristics may be given exactly asdesired.

That is, the above material containing Si, and C and/or O, optionallytogether with H and/or X as constituent atoms can take various formsfrom crystalline to amorphous and show electrical properties fromconductive through semiconductive to insulating and photoconductiveproperties from photoconductive to non-photoconductive depending on thepreparation conditions. Therefore, in the present invention, thepreparation conditions are strictly selected as desired so that theremay be formed the amorphous material for constitution of the secondlayer (II) having desired characteristics depending on the purpose. Forexample, when the second layer (II) is to be provided primarily for thepurpose of improvement of dielectric strength, the aforesaid amorphousmaterial is prepared as an amorphous material having marked electricinsulating behaviours under the use environment.

Alternatively, when the primary purpose for provision of the secondlayer (II) is improvement of continuous repeated use characteristics orenvironmental use characteristics, the degree of the above electricinsulating property may be alleviated to some extent and the aforesaidamorphous material may be prepared as an amorphous material havingsensitivity to some extent to the light irradiated.

In forming the second layer (II) consisting of the aforesaid amorphousmaterial on the surface of the first layer (I), the substratetemperature during layer formation is an important factor havinginfluences on the structure and the characteristics of the layer to beformed, and it is desired in the present invention to control severelythe substrate temperature during layer formation so that the secondlayer (II) having intended characteristics may be prepared as desired.

As the substrate temperature in forming the second layer (II) foraccomplishing effectively the objects in the present invention, theremay be selected suitably the optimum temperature range in conformitywith the method for forming the second layer (II) in carrying outformation of the second layer (II), preferably 20° to 400° C., morepreferably 50° to 350° C., most preferably 100° to 300° C. For formationof the second layer (II), the glow discharge method or the sputteringmethod may be advantageously adopted, because severe control of thecomposition ratio of atoms constituting the layer or control of layerthickness can be conducted with relative ease as compared with othermethods. In case when the second layer (II) is to be formed according tothese layer forming methods, the discharging power during layerformation is one of important factors influencing the characteristics ofthe above amorphous material constituting the second layer (II) to beprepared, similarly as the aforesaid substrate temperature.

The discharging power condition for preparing effectively the amorphousmaterial for constitution of the second layer (II) havingcharacteristics for accomplishing the objects of the present inventionwith good productivity may preferably be 1.0 to 300 W, more preferably2.0 to 250 W, most preferably 5.0 to 200 W.

The gas pressure in a deposition chamber may preferably be 0.01 to 1Torr, more preferably 0.1 to 0.5 Torr.

In the present invention, the above numerical ranges may be mentioned aspreferable numerical ranges for the substrate temperature, dischargingpower for preparation of the second layer (II). However, these factorsfor layer formation should not be determined separately independently ofeach other, but it is desirable that the optimum values of respectivelayer forming factors should be determined based on mutual organicrelationships so that the second layer (II) having desiredcharacteristics may be formed.

The respective contents of carbon atoms, oxygen atoms or both thereof inthe second layer (II) in the photoconductive member of the presentinvention are important factors for obtaining the desiredcharacteristics to accomplish the objects of the present invention,similarly as the conditions for preparation of the second layer (II).The respective contents of carbon atoms and/or oxygen atoms contained inthe second layer (II) in the present invention are determined as desireddepending on the amorphous material constituting the second layer (II)and its characteristics.

More specifically, the amorphous material represented by the aboveformula a-(Si_(x) C_(1-x))_(y) (H,X)_(1-y) may be broadly classifiedinto an amorphous material constituted of silicon atoms and carbon atoms(hereinafter) written as "a-Si_(a) C_(1-a) ", where 0<a<1), an amorphousmaterial constituted of silicon atoms, carbon atoms and hydrogen atoms(hereinafter written as a-(Si_(b) C_(1-b))_(c) H_(1-c), where 0<b, c<1)and an amorphous material constituted of silicon atoms, carbon atoms,halogen atoms and optionally hydrogen atoms (hereinafter written as"a-(Si_(d) C_(1-d))_(e) (H,X)_(1-e) ", where 0<d, e<1).

In the present invention, when the second layer (II) is to beconstituted of a-Si_(a) C_(1-a), the content of carbon atoms in thesecond layer (II) may generally be 1×10⁻³ to 90 atomic %, morepreferably 1 to 80 atomic %, most preferably 10 to 75 atomic %, namelyin terms of representation by a in the above a-Si_(a) C_(1-a), a beingpreferably 0.1 to 0.99999, more preferably 0.2 to 0.99, most preferably0.25 to 0.9.

In the present invention, when the second layer (II) is to beconstituted of a-(Si_(b) C_(1-b))_(c) H_(1-c), the content of carbonatoms in the second layer (II) may preferably be 1×10⁻³ to 90 atomic %,more preferably 1 to 90 atomic %, most preferably 10 to 80 atomic %, thecontent of hydrogen atoms preferably 1 to 40 atomic %, more preferably 2to 35 atomic %, most preferably 5 to 30 atomic %, and thephotoconductive member formed when the hydrogen content is within theseranges can be sufficiently applicable as excellent one in practicalaspect.

That is, in terms of the representation by the above a-(Si_(b)C_(1-b))_(c) H_(1-c), b should preferably be 0.1 to 0.99999, morepreferably 0.1 to 0.99, most preferably 0.2 to 0.9, and c preferably 0.6to 0.99, more preferably 0.65 to 0.98, most preferably 0.7 to 0.95.

When the second layer (II) to be constituted of a-(Si_(d) C_(1-d))_(e)(H,X)_(1-e), the content of carbon atoms in the second layer (II) maypreferably be 1×10⁻³ to 90 atomic %, more preferably 1 to 90 atomic %,most preferably 10 to 85 atomic %, the content of halogen atomspreferably 1 to 20 atomic %, more preferably 1 to 18 atomic %, mostpreferably 2 to 15 atomic %. When the content of halogen atoms is withinthese ranges, the photoconductive member prepared is sufficientlyapplicable in practical aspect. The content of hydrogen atoms optionallycontained may preferably be 19 atomic % or less, more preferably 13atomic % or less.

That is in terms of representation by d and e in the above a-(Si_(d)C_(1-d))_(e) (H,X)_(1-e), d should preferably be 0.1 to 0.99999, morepreferably 0.1 to 0.99, most preferably 0.15 to 0.9, and e preferably0.8 to 0.99, more preferably 0.82 to 0.99, most preferably 0.85 to 0.98.

On the other hand, the amorphous material represented by the aboveformula a-(Si_(x) O_(1-x))_(y) (H,X)_(1-y) may be broadly classifiedinto an amorphous material constituted of silicon atoms and oxygen atoms(hereinafter written as "a-Si_(a) O_(1-a) ", where 0<a<1), an amorphousmaterial constituted of silicon atoms, oxygen atoms and hydrogen atoms(hereinafter written as a-(Si_(b) O_(1-b))_(c) H_(1-c), where 0<b, c<1)and an amorphous material constituted of silicon atoms, oxygen atoms,halogen atoms and optionally hydrogen atoms (hereinafter written as"a-(Si_(d) O_(1-d))_(e) (H,X)_(1-e) ", where 0<d, e<1).

In the present invention, when the second layer (II) is to beconstituted of a-Si_(a) O_(1-a), the content of oxygen atoms in thesecond layer (II) may preferably be 0.33 to 0.99999, more preferably 0.5to 0.99, most preferably 0.6 to 0.9, in terms of a in the above formulaa-Si_(a) O_(1-a).

In the present invention, when the second layer (II) is to beconstituted of a-(Si_(b) O_(1-b))_(c) H_(1-c), the content of oxygenatoms may preferably be such that b in the above formula a-(Si_(b)O_(1-b))_(c) H_(1-c) may preferably be 0.33 to 0.99999, more preferablybe 0.5 to 0.9, most preferably 0.6 to 0.9, and c preferably 0.6 to 0.99,more preferably 0.65 to 0.98, most preferably 0.7 to 0.95.

When the second layer (II) is to be constituted of a-(Si_(d)O_(1-d))_(e) (H,X)_(1-e), the content of oxygen atoms may preferably besuch that d in the above formula a-(Si_(d) O_(1-d))_(e) (H,X)_(1-e) maypreferably be 0.33 to 0.99999, more preferably be 0.5 to 0.99, mostpreferably 0.6 to 0.9, and e preferably 0.8 to 0.99, more preferably0.82 to 0.99, most preferably 0.85 to 0.98.

The range of the numerical value of layer thickness of the second layer(II) should desirably be determined depending on the intended purpose soas to effectively accomplish the objects of the present invention.

The layer thickness of the second layer (II) is also required to bedetermined as desired suitably with due considerations about therelationships with the contents of oxygen atoms, the relationship withthe layer thickness of the first layer (I), as well as other organicrelationships with the characteristics required for respective layerregions.

In addition, it is also desirable to have considerations from econimicalpoint of view such as productivity or capability of bulk production.

The second layer (II) in the present invention is desired to have alayer thickness preferably of 0.003 to 30μ, more preferably 0.004 to20μ, most preferably 0.005 to 10μ.

In the photoconductive member of the present invention, desiredconductivity characteristic may be imparted to the first layer region(G) by incorporating a substance (C) for controlling conductivity asdescribed above in the first layer region (G).

The substance (C) for controlling conductivity to be incorporated in thefirst layer region (G) may be contained in the first layer region (G)either evenly throughout the whole layer region or locally in a part ofthe layer region (G).

In the present invention, when the substance (C) for controllingconductivity is contained in the first layer region (G) so as to existlocally in a part of the layer region (G), the layer region (PN)containing said substance (C) should desirably be provided as the endlayer region of the first layer region (G). In particular, when the saidlayer region (PN) is provided as the end layer region on the substrateside of the first layer region (G), it is possible to inhibiteffectively injection of charges of a specific polarity from thesubstrate into the light receiving layer by selecting adequately theaforesaid substance (C) to be contained in the layer region (PN) and itsamount as desired.

In the present invention, when the substance (C) for controllingconductivity is contained in the first layer region (G) constituting apart of the light receiving layer evenly throughout the whole region orlocally in the layer thickness direction, it is further possible toincorporate the above substance (C) in the second layer region (S) whichis provided on the first layer region (G).

When the above substance (C) is contained in the second layer region(S), the substance (C) to be contained in the second layer region (S),its amount and the manner in which it is contained may suitably bedetermined depending on the substance (C) contained in the first layerregion (G), its amount and the manner in which it is contained.

In the present invention, when the above substance (C) is contained inthe second layer region (S), it is preferred that the above substance(C) should be contained at least on the layer region including thecontacted interface with the first layer region (G).

Otherwise, the above substance (C) may also be contained in the secondlayer region (S) evenly throughout the whole region or alternativelyuniformly only in a part of the layer region.

Thus, when the substance (C) for controlling conductivity is containedin both of the first layer region (G) and the second layer region (S),it is desirable that the layer region containing the above substance (C)in the first layer region (G) and the layer region containing the abovesubstance (C) in the second layer region (S) should be provided so as tobe in contact with each other. The substance (C) contained in the firstlayer region (G) and that in the second layer region (S) may be of thesame species or different, and their amounts may also be the same ordifferent in respective layer regions.

However, in the case when the above substance (C) contained in therespective regions is of the same kind, it is preferable to increasesufficiently the content in the first layer region (G) or to incorporatesubstances with different electrical characteristics in respectivedesired layer regions.

Thus, in the present invention, by provision of a layer region (PN)containing a substance (C) for controlling conductivity by incorporatingthe substance (C) in the first layer region (G) and/or the second layerregion (S), the conductivity characteristic can be controlled asdesired, but its content should desirably be determined as follows.

That is, in the present invention, the content of the substance (C) forcontrolling conductivity in the layer region (PN) may be suitably beselected depending on the conductivity required for said layer region(PN), or the relationships with characteristics of other layer regionsprovided in direct contact with said layer region (PN) or thecharacteristics at the contacted interface with said other layerregions.

In the present invention, the content of the substance (C) forcontrolling conductivity contained in the layer region (PN) shouldpreferably be 0.01 to 5×10⁴ atomic ppm, more preferably 0.5 to 1×10⁴atomic ppm, most preferably 1 to 5×10³ atomic ppm.

In the present invention, by making the content of the substance (C) forcontrolling conductivity in the layer region (PN) preferably 30 atomicppm or more, more preferably 50 atomic ppm or more, most preferably 100atomic ppm or more, for example, in the case when said substance to beincorporated is a p-type impurity as mentioned above, migration ofelectrons injected from the substrate side into the light receivinglayer can be effectively inhibited when the free surface of the lightreceiving layer is subjected to the charging treatment to ⊕ polarity. Onthe other hand, when the substance to be incorporated is a n-typeimpurity, migration of positive holes injected from the substrate sideinto the light receiving layer can be effectively inhibited when thefree surface of the light receiving layer is subjected to the chargingtreatment to ⊖ polarity.

In the case as mentioned above, the layer region (Z) at the portionexcluding the above layer region (PN) as described above may contain asubstance for controlling conductivity of the other polarity, or asubstance for controlling conductivity characteristics of the samepolarity may be contained therein in an amount by far smaller than thatpractically contained in the layer region (PN).

In such a case, the content of the substance (C) for controllingconductivity contained in the above layer region (Z) can be determinedadequately as desired depending on the polarity or the content of thesubstance contained in the layer region (PN), but it is preferably 0.001to 1000 atomic ppm, more preferably 0.05 to 500 atomic ppm, mostpreferably 0.1 to 200 atomic ppm.

In the present invention, when the same kind of a substance forcontrolling conductivity is contained in the layer region (PN) and thelayer region (Z), the content in the layer region (Z) should preferablybe 30 atomic ppm or less.

In the present invention, it is also possible to provide a layer regioncontaining a substance for controlling conductivity having one polarityand a layer region containing a substance for controlling conductivityhaving the other polarity in direct contact with each other, thusproviding a so called depletion layer at said contact region. In short,for example, a layer region containing the aforesaid p-type impurity anda layer region containing the aforesaid n-type impurity are provided inthe light receiving layer in direct contact with each other to form theso called p-n junction, whereby a depletion layer can be provided.

The photoconductive member of the present invention designed to havesuch a layer constitution as described in detail above can solve all ofthe various problems as mentioned above and exhibit very excellentelectrical, optical, photoconductive characteristics, dielectricstrength and use environment characteristics.

In particular, the photoconductive member of the present invention isfree from any influence from residual potential on image formation whenapplied for an image forming member for electrophotography, with itselectrical characteristics being stable with high sensitivity, having ahigh SN ratio as well as excellent light fatigue resistance andexcellent repeated use characteristic and being capable of providingimages of high quality of high density, clear halftone and highresolution repeatedly and stably.

Also, in the photoconductive member of the present invention, the firstlayer formed on the substrate is itself tough and markedly excellent inadhesion to the substrate, and therefore it can be used continuouslyrepeatedly at high speed for a long time.

Further, the photoconductive member of the present invention is high inphotosensitivity over all the visible light region, particularlyexcellent in matching to semiconductor laser, excellent in interferenceinhibition and rapid in response to light.

Next, an example of the process for producing the photoconductive memberof this invention is to be briefly described.

FIG. 12 shows one example of a device for producing a photoconductivemember.

In the gas bombs 1202 to 1206, there are hermetically contained startinggases for formation of the photosensitive member of the presentinvention. For example, 1202 is a bomb containing SiH₄ gas diluted withHe (purity: 99.999%, hereinafter abbreviated as SiH₄ /He), 1203 is abomb containing GeH₄ gas diluted with He (purity: 99.999%, hereinafterabbreviated as GeH₄ /He), 1204 is a bomb containing SiF₄ gas dilutedwith He (purity: 99.999%, hereinafter abbreviated as SiF₄ /He), 1205 isa bomb containing NH₃ gas (purity: 99.999%) and 1206 is a bombcontaining H₂ gas (purity: 99.999%).

For allowing these gases to flow into the reaction chamber 1201, onconfirmation of the valves 1222-1226 of the gas bombs 1202-1206 and theleak valve 1235 to be closed, and the inflow valves 1212-1216, theoutflow valves 1217-1221 and the auxiliary valves 1232, 1233 to beopened, the main valve 1234 is first opened to evacuate the reactionchamber 1201 and the gas pipelines. As the next step, when the readingon the vacuum indicator 1236 becomes 5×10⁻⁶ Torr, the auxiliary valves1232, 1233 and the outflow valves 1217-1221 are closed.

Referring now to an example of forming the first layer (I) on thecylindrical substrate 1237, SiH₄ /He gas from the gas bomb 1202, GeH₄/He gas from the gas bomb 1203 and NH₃ gas from the gas bomb 1205 arepermitted to flow into the mass-flow controllers 1207, 1208, 1209respectively, by opening the valves 1222, 1223, 1224 and controlling thepressures at the outlet pressure gauges 1227, 1228, 1229 to 1 Kg/cm² andopening gradually the inflow valves 1212, 1213, 1214 respectively.Subsequently, the outflow valves 1217, 1218, 1219 and the auxiliaryvalve 1232 are gradually opened to permit respective gases to flow intothe reaction chamber 1201. The outflow valves 1217, 1218, 1219 arecontrolled so that the flow rate ratio of SiH₄ /He, GeH₄ /He and NH₃gases may have a desired value and opening of the main valve 1234 isalso controlled while watching the reading on the vacuum indicator 1236so that the pressure in the reaction chamber 1201 may reach a desiredvalue. And, after confirming that the temperature of the substrate 1237is set at 50°- 400° C. by the heater 1238, the power source 1240 is setat a desired power to excite glow discharge in the reaction chamber1201, thereby forming a first layer region (G) on the substrate 1237.When the first layer region (G) is formed to a desired thickness,following the same conditions and the procedure except for completelyclosing the outflow valve 1218 and changing the discharging conditions,if desired, glow discharging is maintained for a desired period of time,whereby the second layer region (S) containing substantially nogermanium atom can be formed on the first layer region (G).

For incorporation of a substance (C) for controlling conductivity in thefirst layer region (G) and/or the second layer region (S), for example,a gas such as B₂ H₆, PH₃, etc. may be added to the gases to beintroduced into the deposition chamber 1201 during formation of thefirst layer region (G) and/or the second layer region (S).

During layer formation, for uniformization of layer formation, thesubstrate 1237 should desirably be rotated by a motor 1239 at a constantspeed.

For incorporation of halogen atoms in the first layer (I), for example,SiF₄ gas may further be added to the above gases in exciting glowdischarging.

Also, when halogen atoms are contained in the first layer (I) withoutincorporation of hydrogen atoms, SiF₄ /He gas and GeF₄ /He gas may beemployed in place of the previous SiH₄ /He gas and GeH₄ /He gas.

As described above, the photoconductive member having the layerstructure as shown in FIG. 1 can be formed. For preparation of thephotoconductive member with the layer structure shown in FIG. 11, thefollowing procedure may be followed.

That is, formation of a second layer (II) on the first layer (I) formedto a desired thickness as described above may be performed by use of,for example, SiH₄ gas and respective gases of C₂ H₄, or/and NO gases,optionally diluted with a diluting gas such as He, according to samevalve operation as in formation of the first layer (I), and excitingglow discharge following the desirable conditions.

For incorporation of halogen atoms in the second layer (II), forexample, SiF₄ gas and C₂ H₄ or/and NO gases, or a gas mixture furtheradded with SiH₄ gas, may be used to form the second layer (II) accordingto the same procedure as described above.

During formation of the respective layers, outflow valves other thanthose for necessary gases should of course be closed. Also, duringformation of respective layers, in order to avoid remaining of the gasemployed for formation of the preceding layer in the reaction chamber1201 and the gas pipelines from the outflow valves 1217-1221 to thereaction chamber, the operation of evacuating the system to high vacuumby closing the outflow valves 1217-1221, opening the auxiliary valves1232, 1233 and opening fully the main valve 1234 is conducted ifnecessary.

Each amount of carbon atoms and/or oxygen atoms contained in the secondlayer (II) can be controlled as desired by, for example, in the case ofglow discharge, changing the flow rate ratio of SiH₄ gas and the gassuch as C₂ H₄ and/or NO to be introduced into the reaction chamber 1201as desired, or in the case of layer formation by sputtering, changingthe sputtering area ratio of silicon wafer to graphite wafer and/or SiO₂wafer or molding a target with the use of a mixture of silicon powderwith graphite powder and/or SiO₂ powder at a desired mixing ratio. Thecontent of halogen atoms (X) contained in the second layer (II) can becontrolled by controlling the flow rate of the starting gas forintroduction of halogen atoms such as SiF₄ gas when introduced into thereaction chamber 1201.

In formation of the above first layer (I), at the stage when a desiredamount of time has been elapsed after initiation of forming said layer,flowing of B₂ H₆ /He gas or NH₃ gas into the deposition chamber can bediscontinued thereby controlling freely the respective layer thicknessesof the layer region (B) containing boron atoms and the layer region (N)containing nitrogen atoms.

Also, by controlling the gas flow rate of NH₃ gas into the depositionchamber 1201 according to a desired change rate curve, the depth profileof nitrogen atoms contained in the layer region (N) can be controlled asdesired.

The present invention is further described by referring to the followingExamples.

EXAMPLE 1

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 1A.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊖ 5.0 KV for 0.3sec., followed immediately by irradiation of a light image. The lightimage was irradiated by means of a tungsten lamp light source at a doseof 2 lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferrd onto a transfer paper by corona charging of ⊖5.0 KV, a clear image of high density with excellent resolution and goodgradation reproducibility was obtained.

EXAMPLE 2

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 1, except for changing the conditions to thoseshown in Table 2A.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 1 except for reversing the charging polarity and the chargepolarity of the developer, respectively. As the result, very clear imagequality was obtained.

EXAMPLE 3

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 1, except for changing the conditions to thoseshown in Table 3A.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 1. As the result, very clear image quality was obtained.

EXAMPLE 4

Example 1 was repeated except that the content of germanium atomscontained in the first layer was varied as shown in Table 4A by varyingthe gas flow rate of GeH₄ /He gas to SiH₄ /He gas to obtain respectiveimage forming members for electrophotography.

For each of the image forming member thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 1 to obtain the results as shown in Table 4A.

EXAMPLE 5

Example 1 was repeated except that the layer thickness of the firstlayer was varied as shown in Table 5A to obtain respective image formingmembers for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 1 to obtain the results as shown in Table 5A.

EXAMPLE 6

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 6A.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊖5.0 KV for 0.3 sec.,followed immediately by irradiation of a light image. The light imagewas irradiated by means of a tungsten lamp light source at a dose of 2lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image PG,72 of high density with excellent resolutionand good gradation reproducibility was obtained.

EXAMPLE 7

For the image forming member for electrophotogarapy prepared under thesame toner image forming conditions as in Example 1 except for usingGaAs type semiconductor laser (10 mW) of 810 nm in place of the tungstenlamp as the light source, image quality evaluation was performed. As theresult, an image of high quality, excellent in resolution and good ingradation reproducibility, could be obtained.

EXAMPLE 8

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 1B.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊕5.0 KV for 0.3 sec.,followed immediately by irradiation of a light image. The light imagewas irradiated by means of a tungsten lamp light source at a dose of 2lux.sec through a transmission type test chart.

Immediately thereafter, ⊖ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊕5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 9

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 8, except for changing the conditions to thoseshown in Table 2B.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 8 except for reversing the charging polarity and the chargepolarity of the developer, respectively. As the result, very clear imagequality was obtained.

EXAMPLE 10

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 8, except for changing the conditions to thoseshown in Table 3B.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 8. As the result, very clear image quality was obtained.

EXAMPLE 11

Example 8 was repeated except that the content of germanium atomscontained in the first layer was varied as shown in Table 4B by varyingthe gas flow rate ratio of GeH₄ /He gas to SiH₄ /He gas to obtainrespective image forming members for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 8 to obtain the results as shown in Table 4B.

EXAMPLE 12

Example 8 was repeated except that the layer thickness of the firstlayer was varied as shown in Table 5B to obtain respective image formingmembers for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 8 to obtain the results as shown in Table 5B.

EXAMPLE 13

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrateunder the conditions shown in Tables 6B to 8B, respectively (Sample Nos.601B, 602B and 603B).

Each of the image forming members thus obtained was set in acharging-exposure testing device and subjected to corona charging at⊖5.0 KV for 0.3 sec., followed immediately by irradiation of a lightimage. The light image was irradiated by means of a tungsten lamp lightsource at a dose of 2 lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 14

By means of the device shown in FIG. 12, image forming members forelecctrophotography were prepared on a cylindrical aluminum substrate inthe same manner as in Example 8 except for employing the conditionsshown in Tables 9B and 10B, respectively (Sample Nos. 701B and 702B).

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 8. As the result, very clear image quality was obtained.

EXAMPLE 15

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrate inthe same manner as in Example 8 except for employing the conditionsshown in tables 11B to 15B, respectively (Sample Nos. 801B to 805B).

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 8. As the result, very clear image quality was obtained.

EXAMPLE 16

For the image forming member for electrophotography prepared under thesame toner image forming conditions as in Example 8 except for usingGaAs type semiconductor laser (10 mW) of 810 nm inplace of the tungstenlamp as in the light source, image quality evaluation was performed. Asthe result, an image of high quality, excellent in resolution and goodin gradation reproducibility, could be obtained.

EXAMPLE 17

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 1C.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊖5.0 KV for 0.3 sec.,followed immediately by irradiation of a light image. The light imagewas irradiated by means of a tungsten lamp light source at a dose of 2lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 18

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 17, except for changing the conditions tothose shown in Table 2C.

For image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 17 except for reversing the charging polarity and the chargepolarity of the developer, respectively. As the result, very clear imagequality was obtained.

EXAMPLE 19

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 17, except for changing the conditions tothose shown in Table 3C.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 17. As the result, very clear image quality was obtained.

EXAMPLE 20

Example 17 was repeated except that the content of germanium atomscontained in the first layer was varied as shown in Table 4C by varyingthe gas flow rate ratio of GeH₄ /He gas to SiH₄ /He gas to obtainrespective image forming members for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 17 to obtain the results as shown in Table 4C.

EXAMPLE 21

Example 17 was repeated except that the layer thickness of the firstlayer was varied as shown in Table 5C to obtain respective image formingmembers for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 17 to obtain the results as shown in Table 5C.

EXAMPLE 22

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrateunder the conditions shown in Table 6C.

Each of the image forming members thus obtained was set in acharging-exposure testing device and subjected to corona charging at⊖5.0 KV for 0.3 sec., followed immediately by irradiation of a lightimage. The light image was irradiated by means of a tungsten lamp lightsource at a does of 2 lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarreir) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 23

For the image forming member for electrophotography prepared under thesame toner image forming conditions as in Example 17 except for usingGaAs type semiconductor laser (10 mW) of 810 nm in place of the tungstenlamp as the light source, image quality evaluation was performed. As theresult, an image of high quality, excellent in resolution and good ingradation reproducibility, could be obtained.

EXAMPLE 24

Following the same conditions and the procedure as in respectiveExamples 17 and 22, except for changing the conditions for preparationof the second layer (II) to the respective conditions as shown in Table7C, image forming members for electrophotography were prepared,respectively (48 Samples of Sample No. 12-101C to 12-108C, 12-601C to12-608C).

The respective image forming members for electrophotography thusprepared were individually set on a copying device, and according to thesame conditions as described in respective Examples, each image formingmember for electrophotography was evaluated for overall image quality ofthe transferred image and its durability when used continuously andrepeatedly.

The results of the overall image quality evaluation and evaluation ofdurability by repeated continuous are for respective samples are shownin Table 8C.

EXAMPLE 25

Various image forming members were prepared according to the same methodas in Example 17, except for varying the content ratio of silicon atomsto carbon atoms in the second layer (II) by varying the target arearatio of silicon wafer to graphite during formation of the second layer(II). For each of the image forming members thus obtained, the steps ofimage formation, developing and cleaning as described in Example 17 wererepeated for about 50,000 times, and thereafter image evaluations wereconducted to obtain the results as shown in Table 9C.

EXAMPLE 26

Various image forming members were prepared according to the same methodas in Example 17, respectively, except for varying the content ratio ofsilicon atoms to carbon atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas to C₂ H₄ gas during formation of the secondlayer (II).

For each of the image forming members thus obtained, the steps up totransfer were repeated for about 50,000 times according to the methodsas described in Example 17, and thereafter image evaluations wereconducted to obtain the results as shown in Table 10C.

EXAMPLE 27

Various image forming members were prepared according to the same methodas in Example 17, respectively, except for varying the content ratio ofsilicon atoms to carbon atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas, SiF₄ gas and C₂ H₄ gas during formation ofthe second layer (II). For each of the image forming members thusobtained, the steps of image formation, developing and cleaning asdescribed in Example 17 were repeated for about 50,000 times, andthereafter image evaluations were conducted to obtain the results asshown in Table 11C.

EXAMPLE 28

Respective image forming members were prepared in the same manner as inExample 17, except for changing the layer thickness of the second layer(II), and the steps of image formation, developing and cleaning asdescribed in Example 17 were repeated to obtain the results as shown inTable 12C.

EXAMPLE 29

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 1D.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊕5.0 KV for 0.3 sec.,followed immediately by irradiation of a light image. The light imagewas irradiated by means of a tungsten lamp light source at a dose of 2lux.sec through a transmission type test chart.

Immediately thereafter, ⊖ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊕5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 30

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 29, except for changing the conditions tothose shown in Table 2D.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 29 except for reversing the charging polarity and the chargepolarity of the developer, respectively. As the result, very clear imagequality was obtained.

EXAMPLE 31

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 29, except for changing the conditions tothose shown in Table 3D.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 29. As the result, very clear image quality was obtained.

EXAMPLE 32

Example 29 was repeated except that the content of germanium atomscontained in the first layer was varied as shown in Table 40 by varyingthe gas flow rate ratio of GeH₄ /He gas to SiH₄ /He gas to obtainrespective image forming members for electropho- tography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 29 to obtain the results as shown in Table 4D.

EXAMPLE 33

Example 29 was repeated except that the layer thickness of the firstlayer was varied as shown in Table 5D to obtain respective image formingmembers for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 29 to obtain the results as shown in Table 5D.

EXAMPLE 34

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrateunder the conditions shown in Tables 6D to 8D, respectively (Sample Nos.601D, 602D and 603D).

Each of the image forming members thus obtained was set in acharging-exposure testing device and subjected to corona charging at⊖5.0 KV for 0.3 sec., followed immediately by irradiation of a lightimage. The light image was irradiated by means of a tungsten lamp lightsource at a dose of 2 lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 35

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrate inthe same manner as in Example 29 except for employing the conditionsshown in Tables 9D and 10D, respectively (Sample Nos. 701D and 702D).

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 29. As the result, very clear image quality was obtained.

EXAMPLE 36

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrate inthe same manner as in Example 29 except for employing the conditionsshown in Tables 11D to 15D, respectively (Sample Nos 801D to 805D).

For each of the image forming members thus obtained, images were formedaccording to the same conditions and procedure as in Example 29. As theresult, very clear image quality was obtained.

EXAMPLE 37

For the image forming member for electrophotography prepared under thesame toner image forming conditions as in Example 29 except for usingGaAs type semiconductor laser (10 mW) of 810 nm in place of the tungstenlamp as the light source, image quality evaluation was performed. As theresult, an image of high quality, excellent in resolution and good ingradation reproducibility, could be obtained.

EXAMPLE 38

Following the same conditions and the procedure as in respective Table1D in Example 29 and Table 6D in Example 34, except for changing theconditions for preparation of the second layer (II) to the respectiveconditions as shown in Table 16D, image forming members forelectrophotography were prepared, respectively (72 Samples of Sample No.12-401D to 12-408D, 12-701D to 12-708D, 12-801D to 12-808D).

The respective image forming members for electrophotography thusprepared were individually set on a copying device, and according to thesame conditions as described in respective Examples, each image formingmember for electrophotography was evaluated for overall image quality ofthe transferred image and its durability when used continuously andrepeatedly.

The results of the overall image quality evaluation and evaluation ofdurability by repeated continuous use for respective samples are shownin Table 17D.

EXAMPLE 39

Various image forming members were prepared according to the same methodas in Example 29, except for varying the content ratio of silicon atomsto carbon atoms in the second layer (II) by varying the target arearatio of silicon wafer to graphite during formation of the second layer(II). For each of the image forming members thus obtained, the steps ofimage formation, developing and cleaning as described in Example 29 wererepeated for about 50,000 times, and thereafter image evaluations wereconducted to obtain the results as shown in Table 18D.

EXAMPLE 40

Various image forming members were prepared according to the same methodas in Example 29, respectively, except for varying the content ratio ofsilicon atoms to carbon atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas to C₂ H₄ gas during formation of the secondlayer (II).

For each of the image forming members thus obtained, the steps up totransfer were repeated for about 50,000 times according to the methodsas described in Example 29, and thereafter image evaluations wereconducted to obtain the results as shown in Table 19D.

EXAMPLE 41

Various image forming members were prepared according to the same methodas in Example 29, respectively, except for varying the content ratio ofsilicon atoms to carbon atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas, SiF₄ gas and C₂ H₄ gas during formation ofthe second layer (II). For each of the image forming members thusobtained, the steps of image formation, developing and cleaning asdescribed in Example 29 were repeated for about 50,000 times, andthereafter image evaluations were conducted to obtain the results asshown in Table 20D.

EXAMPLE 42

Respective image forming members were prepared in the same manner as inExample 29, except for changing the layer thickness of the second layer(II), and the steps of image formation, developing and cleaning asdescribed in Example 29 were repeated to obtain the results as shown inTable 21D.

EXAMPLE 43

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 1E.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊖5.0 KV for 0.3 sec.,followed immediately by irradiation of a light image. The light imagewas irradiated by means of a tungsten lamp light source at a dose of 2lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 44

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 43, except for changing the conditions tothose shown in Table 2E.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 43 except for reversing the charging polarity and the chargepolarity of the developer, respectively. As the result, very clear imagequality was obtained.

EXAMPLE 45

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 43, except for changing the conditions tothose shown in Table 3E.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 43. As the result, very clear image quality was obtained.

EXAMPLE 46

Example 43 was repeated except that the content of germanium atomscontained in the first layer was varied as shown in Table 4E by varyingthe gas flow rate ratio of GeH₄ /He gas to SiH₄ /He gas to obtainrespective image forming members for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 43 to obtain the results as shown in Table 4E.

EXAMPLE 47

Example 43 was repeated except that the layer thickness of the firstlayer was varied as shown in Table 5E to obtain respective image formingmembers for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 43 to obtain the results as shown in Table 5E.

EXAMPLE 48

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrateunder the conditions shown in Table 6E.

Each of the image forming members thus obtained was set in acharging-exposure testing device and subjected to corona charging at⊖5.0 KV for 0.3 sec., followed immediately by irradiation of a lightimage. The light image was irradiated by means of a tungsten lamp lightsource at a dose of 2 lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 49

For the image forming member for electrophotography prepared under thesame toner image forming conditions as in Example 43 except for usingGaAs type semiconductor laser (10 mW) of 810 nm in place of the tungstenlamp as the light source, image quality evaluation was performed. As theresult, an image of high quality, excellent in resolution and good ingradation reproducibility, could be obtained.

EXAMPLE 50

Following the same conditions and the procedure as in respectiveExamples 44, 45 and 47, except for changing the conditions forpreparation of the second layer (II) to the respective conditions asshown in Table 7E, image forming members for electrophotography wereprepared, respectively (24 Samples of Sample No. 11-401E to 11-408E,11-501E to 11-508E, 11-601E to 11-608E).

The respective image forming members for electrophotography thusprepared were individually set on a copying device, and according to thesame conditions as described in respective Examples, each image formingmember for electrophotography was evaluated for overall image quality ofthe transferred image and its durability when used continuously andrepeatedly.

The results of the overall image quality evaluation and evaluation ofdurability by repeated continuous use for respective samples are shownin Table 8E.

EXAMPLE 51

Various image forming members were prepared according to the same methodas in Example 43, except for varying the content ratio of silicon atomsto oxygen atoms in the second layer (II) by varying the target arearatio of silicon wafer to Si0₂ during formation of the second layer(II). For each of the image forming members thus obtained, the steps ofimages formation, developing and cleaning as described in Example 43were repeated for about 50,000 times, and thereafter image evaluationswere conducted to obtain the results as shown in Table 9E.

EXAMPLE 52

Various image forming members were prepared according to the same methodas in Example 43, respectively, except for varying the content ratio ofsilicon atoms to oxygen atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas to NO gas during formation of the secondlayer (II).

For each of the image forming members thus obtained, the steps up totransfer were repeated for about 50,000 times according to the methodsas described in Example 43, and thereafter image evaluations wereconducted to obtain the results as shown in Table 10E.

EXAMPLE 53

Various image forming members were prepared according to the same methodas in Example 43, respectively, except for varying the content ratio ofsilicon atoms to carbon atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas, SiF₄ gas and NO gas during formation of thesecond layer (II). For each of the image forming members thus obtained,the steps of image formation, developing and cleaning as described inExample 43 were repeated for about 50,000 times, and thereafter imageevaluations were conducted to obtain the results as shown in Table 11E.

EXAMPLE 54

Respective image forming members were prepared in the same manner as inExample 43, except for changing the layer thickness of the second layer(II), and the steps of image formation, developing and cleaning asdescribed in Example 43 were repeated to obtain the results as shown inTable 12E.

EXAMPLE 55

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared on a cylindrical aluminum substrateunder the conditions shown in Table 1F.

The image forming member thus obtained was set in a charging-exposuretesting device and subjected to corona charging at ⊕5.0 KV for 0.3 sec.,followed immediately by irradiation of a light image. The light imagewas irradiated by means of a tungsten lamp light source at a dose of 2lux.sec through a transmission type test chart.

Immediately thereafter, ⊖ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊕5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 56

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formation in thesame manner as in Example 55, except for changing the conditions tothose shown in Table 2F.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 55 except for reversing the charging polarity and the chargepolarity of the developer, respectively. As the result, very clear imagequality was obtained.

EXAMPLE 57

By means of the device shown in FIG. 12, an image forming member forelectrophotography was prepared by conducting layer formtion in the samemanner as in Example 55, except for changing the conditions to thoseshown in Table 3F.

For the image forming member thus obtained, an image was formed on atransfer paper according to the same conditions and procedure as inExample 55. As the result, very clear image quality was obtained.

EXAMPLE 58

Example 55 was repeated except that the content of germanium atomscontained in the first layer was varied as shown in Table 4F by varyingthe gas flow rate ratio of GeH₄ /He gas to SiH₄ /He gas to obtainrespective image forming members for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 55 to obtain the results as shown in Table 4F.

EXAMPLE 59

Example 55 was repeated except that the layer thickness of the firstlayer was varied as shown in Table 5F to obtain respective image formingmembers for electrophotography.

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 55 to obtain the results as shown in Table 5F.

EXAMPLE 60

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrateunder the conditions shown in Tables 6F to 8F, respectively (Sample Nos.601F, 602F and 603F).

Each of the image forming members thus obtained was set in acharging-exposure testing device and subjected to corona charging at⊖5.0 KV for 0.3 sec., followed immediately by irradiation of a lightimage. The light image was irradiated by means of a tungsten lamp lightsource at a dose of 2 lux.sec through a transmission type test chart.

Immediately thereafter, ⊕ chargeable developer (containing toner andcarrier) was cascaded on the surface of the image forming member to givea good toner image on the surface of the image forming member. When thetoner image was transferred onto a transfer paper by corona charging of⊖5.0 KV, a clear image of high density with excellent resolution andgood gradation reproducibility was obtained.

EXAMPLE 61

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrate inthe same manner as in Example 55 except for employing the conditionsshown in Tables 9F and 10F, respectively (Sample Nos. 701F and 702F).

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 55. As the result, very clear image quality was obtained.

EXAMPLE 62

By means of the device shown in FIG. 12, image forming members forelectrophotography were prepared on a cylindrical aluminum substrate inthe same manner as in Example 55 except for employing the conditionsshown in Tables 11F to 15F, respectively (Sample Nos. 801F to 805F).

For each of the image forming members thus obtained, images were formedon a transfer paper according to the same conditions and procedure as inExample 55. As the result, very clear image quality was obtained.

EXAMPLE 63

For the image forming member for electrophotography prepared under thesame toner image forming conditions as in Example 55 except for usingGaAs type semiconductor laser (10 mW) of 810 nm in place of the tungstenlamp as the light source, image quality evaluation was performed. As theresult, an image of high quality, excellent in resolution and good ingradation reproducibility, could be obtained.

EXAMPLE 64

Following the same conditions and the procedure as in respectiveExamples 55, 56 and 57, except for changing the conditions forpreparation of the second layer (II) to the respective conditions asshown in Table 16F, image forming members for electrophotography wereprepared, respectively (24 Samples of Sample No. 11-101F to 11-108F,11-201F to 11-208F, 11-301F to 11-308F).

The respective image forming members for electrophotography thusprepared were individually set on a copying device, and according to thesame conditions as described in respective Examples, each image formingmember for electrophotography was evaluated for overall image quality ofthe transferred image and its durability when used continuously andrepeatedly.

The results of the overall image quality evaluation and evaluation ofdurability by repeated continuous use for respective samples are shownin Table 17F.

EXAMPLE 65

Various image forming members were prepared according to the same methodas in Example 55, except for varying the content ratio of silicon atomsto oxygen atoms in the second layer (II) by varying the target arearatio of silicon wafer to SiO₂ and also the mixing ratio of Ar to NOduring formation of the second layer (II). For each of the image formingmembers thus obtained, the steps of image formation, developing andcleaning as described in Example 55 were repeated for about 50,000times, and thereafter image evaluations were conducted to obtain theresults as shown in Table 18F.

EXAMPLE 66

Various image forming members were prepared according to the same methodas in Example 55, respectively, except for varying the content ratio ofsilicon atoms to oxygen atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas to NO gas during formation of the secondlayer (II).

For each of the image forming members thus obtained, the steps up totransfer were repeated for about 50,000 times according to the methodsas described in Example 55, and thereafter image evaluations wereconducted to obtain the results as shown in Table 19F.

EXAMPLE 67

Various image forming members were prepared according to the same methodas in Example 55, respectively, except for varying the content ratio ofsilicon atoms to oxygen atoms in the second layer (II) by varying theflow rate ratio of SiH₄ gas, SiF₄ gas and NO gas during formation of thesecond layer (II). For each of the image forming members thus obtained,the steps of image formation, developing and cleaning as described inExample 55 were repeated for about 50,000 times, and thereafter imageevaluations were conducted to obtain the results as shown in Table 20F.

EXAMPLE 68

Respective image forming members were prepared in the same manner as inExample 29, except for changing the layer thickness of the second layer(II), and the steps of image formation, developing and cleaning asdescribed in Example 55 were repeated to obtain the results as shown inTable 21F.

The common layer forming conditions in the respective Examples of thepresent invention are shown below:

Substrate temperature:

Germanium atom (Ge) containing layer . . . 200° C.

No germanium atom (Ge) containing layer . . . about 250° C.

Discharging frequency: 13.56 MHz

Inner pressure in reaction chamber during the reaction: 0.3 Torr.

                                      TABLE 1A                                    __________________________________________________________________________                                             Discharg-                                                                           Layer for-                                                                          Layer                    Layer  Gases    Flow rate                ing power                                                                           mation rate                                                                         thick-                   constitution                                                                         employed (SCCM)    Flow rate ratio                                                                              (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)               __________________________________________________________________________    First layer                                                                          SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/1                                                                   0.18  5     3                               GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                  NH.sub.3                                                               Second layer                                                                         SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200          0.18  15    15                       __________________________________________________________________________

                                      TABLE 2A                                    __________________________________________________________________________                                              Discharg-                                                                           Layer for-                                                                          Layer                   Layer  Gases    Flow rate                 ing power                                                                           mation rate                                                                         thick-                  constitution                                                                         employed (SCCM)    Flow rate ratio (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)              __________________________________________________________________________    First layer                                                                          SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                   0.18  5     5                              GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3           (linearly reduced)                                  Second layer                                                                         SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                   0.18  5     1                              GeH.sub.4 /He = 0.05                                                   Third layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200           0.18  15    15                      __________________________________________________________________________

                                      TABLE 3A                                    __________________________________________________________________________                                             Discharg-                                                                           Layer for-                                                                          Layer                    Layer  Gases    Flow rate                ing power                                                                           mation rate                                                                         thick-                   constitution                                                                         employed (SCCM)    Flow rate ratio                                                                              (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)               __________________________________________________________________________    First layer                                                                          SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 4/10                                                                  0.18  5     2                               GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                  NH.sub.3                                                               Second layer                                                                         SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 2/100                                                                  0.18  15    2                               NH.sub.3           B.sub.2 H.sub.6 /SiH.sub.4 = 1                                                × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                        Third layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 1                                                × 10.sup.-5                                                                            0.18  15    15                              B.sub.2 H.sub.6 /He = 10.sup.- 3                                       __________________________________________________________________________

                  TABLE 4A                                                        ______________________________________                                        Sample No.                                                                            401A    402A   403A  404A 405A  406A 407A                             ______________________________________                                        Ge content                                                                            1       3      5     10   40    60   90                               (atomic %)                                                                    Evaluation                                                                            Δ ○                                                                             ⊚                                                                    ⊚                                                                   ⊚                                                                    ○                                                                           Δ                          ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                              Δ: Practically satisfactory                                        

                  TABLE 5A                                                        ______________________________________                                        Sample       501A    502A    503A  504A  505A                                 ______________________________________                                        Layer thickness(μ)                                                                      0.1     0.5     1     2     5                                    Evaluation   ○                                                                              ○                                                                              ⊚                                                                    ⊚                                                                    ○                             ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                         

                                      TABLE 6A                                    __________________________________________________________________________                                             Discharg-                                                                           Layer for-                                                                          Layer                    Layer  Gases    Flow rate                ing power                                                                           mation rate                                                                         thick-                   constitution                                                                         employed (SCCM)    Flow rate ratio                                                                              (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)               __________________________________________________________________________    First layer                                                                          SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 4/10                                                                  0.18  5     2                               GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                  NH.sub.3                                                               Second layer                                                                         SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         PH.sub.3 /SiH.sub.4 = 1 × 10.sup.-7                                                    0.18  15    20                              PH.sub.3 /He = 10.sup.-3                                               __________________________________________________________________________

                                      TABLE 1B                                    __________________________________________________________________________                                                 Discharg-                                                                            Layer                                                                               Layer               Layer   Gases    Flow rate                   ing power                                                                            mation                                                                              thick-              constitution                                                                          employed (SCCM)     Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    First layer                                                                           SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18   15    20                  __________________________________________________________________________

                                      TABLE 2B                                    __________________________________________________________________________                                                 Discharg-                                                                            Layer                                                                               Layer               Layer   Gases    Flow rate                   ing power                                                                            mation                                                                              thick-              constitution                                                                          employed (SCCM)     Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    First layer                                                                           SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   15    19                          GeH.sub.4 /He = 0.05                                                  Third layer                                                                           SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18   15    5                   __________________________________________________________________________

                                      TABLE 3B                                    __________________________________________________________________________                                                 Discharg-                                                                            Layer                                                                               Layer               Layer   Gases    Flow rate                   ing power                                                                            mation                                                                              thick-              constitution                                                                          employed (SCCM)     Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    First layer                                                                           SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     2                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                          B.sub.2 H.sub.6 /SiH.sub.4 = 2 ×                                        10.sup.-4        0.18   15    20                          B.sub.2 H.sub.6 /He = 10.sup.-3                                       __________________________________________________________________________

                  TABLE 4B                                                        ______________________________________                                        Sample No.                                                                            401B    402B   403B 404B 405B 406B 407B 408B                          ______________________________________                                        GeH.sub.4 /SiH.sub.4                                                                  5/100   1/10   2/10 4/10 5/10 7/10 8/10 1/1                           Flow rate                                                                     ratio                                                                         Ge content                                                                            4.3     8.4    15.4 26.7 32.3 38.9 42   47.6                          (atomic %)                                                                    Evaluation                                                                            ⊚                                                                      ⊚                                                                     ⊚                                                                   ⊚                                                                   ⊚                                                                   ○                                                                           ○                                                                           ○                      ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                         

                  TABLE 5B                                                        ______________________________________                                        Sample No.                                                                            501B   502B    503B 504B 505B 506B 507B 508B                          ______________________________________                                        Layer   30Å                                                                              500Å                                                                              0.1μ                                                                            0.3μ                                                                            0.8μ                                                                            3μ                                                                              4μ                                                                              5μ                         thickness                                                                     Evaluation                                                                            Δ                                                                              ○                                                                              ⊚                                                                   ⊚                                                                   ⊚                                                                   ○                                                                           ○                                                                           Δ                       ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                              Δ: Practically satisfactory                                        

                                      TABLE 6B                                    __________________________________________________________________________    (Sample No. 601B)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer   Gases    Flow rate                   ing power                                                                            mation                                                                              thick-              constitution                                                                          employed (SCCM)     Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    First layer                                                                           SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 5/10                                                                    0.18   5     2                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                          PH.sub.3 /SiH.sub.4 = 9 × 10.sup.-5                                                      0.18   15    20                          PH.sub.3 /He = 10.sup.-3                                              __________________________________________________________________________

                                      TABLE 7B                                    __________________________________________________________________________    (Sample No. 602B)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer   Gases    Flow rate                   ing power                                                                            mation                                                                              thick-              constitution                                                                          employed (SCCM)     Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    First layer                                                                           SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     15                          GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 8                                  × 10.sup.-4                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                          PH.sub.3 /SiH.sub.4 = 1 × 10.sup.-5                                                      0.18   15    5                           PH.sub.3 /He = 10.sup.-3                                              __________________________________________________________________________

                                      TABLE 8B                                    __________________________________________________________________________    (Sample No. 603B)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer   Gases    Flow rate                   ing power                                                                            mation                                                                              thick-              constitution                                                                          employed (SCCM)     Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    First layer                                                                           SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                          B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4        0.18   15    20                          B.sub.2 H.sub.6 /He = 10.sup.-3                                       __________________________________________________________________________

                                      TABLE 9B                                    __________________________________________________________________________    (Sample No. 701B)                                                                                                          Discharg-                                                                           Layer                                                                                Layer               Layer   Gases     Flow rate                  ing power                                                                           mation                                                                               thick-              constitution                                                                          employed  (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   First layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  5      1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  5      19                          GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =                                    1/10.sup.-5                                               B.sub.2 H.sub.5 /He = 10.sup.-3                                       Third layer                                                                           SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4        0.18  15     5                           B.sub.2 H.sub.6 /He = 10.sup.-3                                       __________________________________________________________________________

                                      TABLE 10B                                   __________________________________________________________________________    (Sample No. 702B)                                                                                                          Discharg-                                                                           Layer                                                                                Layer               Layer   Gases     Flow rate                  ing power                                                                           mation                                                                               thick-              constitution                                                                          employed  (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   First layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(SiH.sub.4 + SiH.sub.4) = 3/100                 NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                           GeH.sub.4 /He = 0.05                                                                              NH.sub.3 /SiH.sub.4 = 3/100                               NH.sub.3                                                              Third layer                                                                           SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 3/100                                                                    0.18  15     1                           NH.sub.3            B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-4                                                 B.sub.2 H.sub.6 /He = 10.sup.-3                                       Fourth layer                                                                          SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-4        0.18  15     15                          B.sub.2 H.sub.6 /He = 10.sup.-3                                       __________________________________________________________________________

                                      TABLE 11B                                   __________________________________________________________________________    (Sample No. 801B)                                                                                                          Discharg-                                                                           Layer                                                                                Layer               Layer   Gases     Flow rate                  ing power                                                                           mation                                                                               thick-              constitution                                                                          employed  (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   First layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18  5      1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(SiH.sub.4 + SiH.sub.4)                                             = 3/100˜                                            NH.sub.3            2.83/100                                          Second layer                                                                          SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18  5      1                           GeH.sub.4 /He = 0.05                                                                              NH.sub.3 /(GeH.sub.4 + SiH.sub.4) =                       NH.sub.3            2.83/100˜0                                  Third layer                                                                           SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200            0.18  15     19                  __________________________________________________________________________     The flow rate ratio NH.sub.3 /(GeH.sub.4 + SiH.sub.4) was reduced             linearly.                                                                

                                      TABLE 12B                                   __________________________________________________________________________    (Sample No. 802B)                                                                                                          Discharg-                                                                           Layer                                                                                Layer               Layer   Gases     Flow rate                  ing power                                                                           mation                                                                               thick-              constitution                                                                          employed  (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   First layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     0.5                         GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-4                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                           NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     0.5                         GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup. -3                                        B.sub.2 H.sub.6 /He = 10.sup.-3                                       Third layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  15     19                          GeH.sub.4 /He = 0.05                                                  Fourth layer                                                                          SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200            0.18  15     15                  __________________________________________________________________________

                                      TABLE 13B                                   __________________________________________________________________________    (Sample No. 803B)                                                                                                          Discharg-                                                                           Layer                                                                                Layer               Layer   Gases     Flow rate                  ing power                                                                           mation                                                                               thick-              constitution                                                                          employed  (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   First layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18  5      1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 1/100˜0                                           NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18  5      1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =                                    5/10.sup.-3                                               B.sub.2 H.sub.6 /He = 10.sup.-3                                       Third layer                                                                           SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 2 ×                                        10.sup.-4        0.18  15     20                          B.sub.2 H.sub.6 /He = 10.sup.-3                                       __________________________________________________________________________

                                      TABLE 14B                                   __________________________________________________________________________    (Sample No. 804B)                                                                                                      Discharg-                                                                           Layer for-                                                                          Layer                    Layer  Gases    Flow rate                ing power                                                                           mation rate                                                                         thick-                   constitution                                                                         employed (SCCM)    Flow rate ratio                                                                              (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ                __________________________________________________________________________                                                         )                        First layer                                                                          SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                  0.18   5     1                              GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /SiH.sub.4 = 3                                                × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 SiH.sub.4 = 3/100˜2.83/100                  NH.sub.3                                                               Second layer                                                                         SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 2.83/100˜0                                                       0.18  15    20                              NH.sub.3           B.sub.2 H.sub.6 /SiH.sub.4 = 3                                                × 10.sup.-4                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                        __________________________________________________________________________     The flow rate ratio NH.sub.3 /SiH.sub.4 was reduced linearly.            

                                      TABLE 15B                                   __________________________________________________________________________    (Sample No. 805B)                                                                                                          Discharg-                                                                           Layer                                                                                Layer               Layer   Gases     Flow rate                  ing power                                                                           mation                                                                               thick-              constitution                                                                          employed  (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   First layer                                                                           SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  5      1                           GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                           NH.sub.3                                                              Second layer                                                                          SiH.sub.4 /He = 0.05                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  5      19                          GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =                                    1/10.sup.-5                                               B.sub.2 H.sub.6 /He = 10.sup.-3                                       Third layer                                                                           SiH.sub.4 /He = 0.5                                                                     SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4        0.18  15     5                           B.sub.2 H.sub.6 /He = 10.sup.-3                                       __________________________________________________________________________     The flow rate ratio NH.sub.3 /(GeH.sub.4 + SiH.sub.4) was reduced             linearly.                                                                

                                      TABLE 1C                                    __________________________________________________________________________                                             Discharg-                                                                           Layer for-                                                                          Layer                    Layer    Gases    Flow rate              ing power                                                                           mation                                                                              thick-                   constitution                                                                           employed (SCCM)    Flow rate ratio                                                                            (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ                __________________________________________________________________________                                                         )                        Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/1                                                                 0.18   5    3                             layer                                                                             GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4)2/100                     NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200        0.18  15    15                            layer                                                                    Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                         SiH.sub.4 /C.sub.2 H.sub.4 = 3/7                                                           0.18  10    0.5                               C.sub.2 H.sub.4                                                      __________________________________________________________________________

                                      TABLE 2C                                    __________________________________________________________________________                                                  Discharg-                                                                           Layer                                                                               Layer               Layer     Gases    Flow rate                  ing power                                                                           mation                                                                              thick-              constitution                                                                            employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                           First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  5     5                         layer                                                                             GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3           (linearly reduced)                                     Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18  5     1                         layer                                                                             GeH.sub.4 /He = 0.05                                                      Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200            0.18  15    15                        layer                                                                   __________________________________________________________________________

                                      TABLE 3C                                    __________________________________________________________________________                                                 Discharg-                                                                           Layer                                                                                Layer               Layer      Gases    Flow rate                ing power                                                                           mation thick-              constitution                                                                             employed (SCCM)    Flow rate ratio                                                                              (W/cm.sup.2)                                                                        (Å/sec)                                                                          ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                           First                                                                              SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 4/10                                                                  0.18  5      2                         layer                                                                              GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                  NH.sub.3                                                                 Second                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 2/100                                                                  0.18  5      2                         layer                                                                              NH.sub.3           B.sub.2 H.sub.6 / SiH.sub.4 = 1 ×                                       10.sup.-5                                                  B.sub.2 H.sub.6 /He = 10.sup.-3                                          Third                                                                              SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-5      0.18  15     15                        layer                                                                              B.sub.2 H.sub.6 /He = 10.sup.-3                                    __________________________________________________________________________

                  TABLE 4C                                                        ______________________________________                                        Sample No.                                                                             401C    402C   403C 404C 405C 406C  407C                             ______________________________________                                        Ge content                                                                             1       3      5    10   40   60    90                               (atomic %)                                                                    Evaluation                                                                             Δ ○                                                                             ⊚                                                                   ⊚                                                                   ⊚                                                                   ○                                                                            Δ                          ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                              Δ: Practically satisfactory                                        

                  TABLE 5C                                                        ______________________________________                                        Sample No.  501C     502C   503C   504C 505C                                  ______________________________________                                        Layer thickness(μ )                                                                    0.1      0.5    1      2    5                                     Evaluation  ○ ○                                                                             ⊚                                                                     ⊚                                                                   ○                              ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                         

                                      TABLE 6C                                    __________________________________________________________________________                                           Discharg-                                                                           Layer for-                                                                          Layer                      Layer    Gases    Flow rate            ing power                                                                           mation                                                                              thick-                     constitution                                                                           employed (SCCM)                                                                              Flow rate ratio                                                                              (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ                  __________________________________________________________________________                                                       )                          Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.005                                                                  GeH.sub.4 = 50                                                                      SiH.sub.4 GeH.sub.4 = 1/100                                                                  0.18   5    2                               layer                                                                             GeH.sub.4 /He = 0.05                                                                         NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                      NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                     GeH.sub.4 /SiH.sub.4 = 50                                                                    0.18  15    20                              layer                                                                             PH.sub.3 /He = 10.sup.-3                                                                     PH.sub.3 /SiH.sub.4 = 1 × 10.sup.-7             Layer (III)                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                     SiH.sub.4 /C.sub.2 H.sub.4 = 3/7                                                             0.18  10    0.5                                 C.sub.2 H.sub.4                                                      __________________________________________________________________________

                                      TABLE 7C                                    __________________________________________________________________________          Gases   Flow rate Flow rate ratio                                                                         Discharging                                                                           Layer thick-                        Condition                                                                           employed                                                                              (SCCM)    or Area ratio                                                                           power (W/cm.sup.2)                                                                    ness(μ)                          __________________________________________________________________________    12-1C Ar      200       Si wafer:graphite =                                                                     0.3     0.5                                                         1.5:8.5                                               12-2C Ar      200       Si wafer:graphite =                                                                     0.3     0.3                                                         0.5:9.5                                               12-3C Ar      200       Si wafer:graphite =                                                                     0.3     1.0                                                         6:4                                                   12-4C SiH.sub.4 /He = 1                                                                     SiH.sub.4 = 15                                                                          SiH.sub.4 :C.sub.2 H.sub.4 =                                                            0.18    0.3                                       C.sub.2 H.sub.4   0.4:9.6                                               12-5C SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 = 100                                                                         SiH.sub.4 :C.sub.2 H.sub.4 =                                                            0.18    1.5                                       C.sub.2 H.sub.4   5:5                                                   12-6C SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 = 150                                                             SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                   0.18    0.5                                       SiF.sub.4 /He = 0.5                                                                             1.5:1.5:7                                                   C.sub.2 H.sub.4                                                         12-7C SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 =  15                                                             SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                   0.18    0.3                                       SiF.sub.4 /He = 0.5                                                                             0.3:0.1:9.6                                                 C.sub.2 H.sub.4                                                         12-8C SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 = 150                                                             SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                   0.18    1.5                                       SiF.sub.4 /He = 0.5                                                                             3:3:4                                                       C.sub.2 H.sub.4                                                         __________________________________________________________________________

                  TABLE 8C                                                        ______________________________________                                        Preparation                                                                   conditions                                                                    for layer (II) Sample No./Evaluation                                          ______________________________________                                        12-1C          12-101C   12-601C                                                              ○  ○   ○                                 12-2C          12-102C   12-602C                                                              ○  ○   ○                                 12-3C          12-103C   12-603C                                                              ○  ○   ○                                 12-4C          12-104C   12-604C                                                             ⊚ ⊚                                                       ⊚ ⊚                    12-5C          12-105C   12-605C                                                             ⊚ ⊚                                                       ⊚ ⊚                    12-6C          12-106C   12-606C                                                             ⊚ ⊚                                                       ⊚ ⊚                    12-7C          12-107C   12-607C                                                              ○  ○   ○                                 12-8C          12-108C   12-608C                                                              ○  ○   ○                                 ______________________________________                                        Sample No.                                                                    Overall image                                                                           Durability                                                          evaluation                                                                              evaluation                                                           Education standard:                                                           ⊚: Excellent                                                    ○ : Good                                                         

                                      TABLE 9C                                    __________________________________________________________________________    Sample No.                                                                             1301C                                                                             1302C                                                                             1303C                                                                             1304C                                                                             1305C                                                                             1306C                                                                             1307C                                        __________________________________________________________________________    Si:C target                                                                            9:1 6.5:3.5                                                                           4:6 2:8 1:9 0.5:9.5                                                                           0.2:9.8                                      (area ratio)                                                                  Si:C     9.7:0.3                                                                           8.8:1.2                                                                           7.3:2.7                                                                           4.8:5.2                                                                           3:7 2:8 0.8:9.2                                      (content ratio)                                                               Image quality                                                                          Δ                                                                           ○                                                                          ⊚                                                                  ⊚                                                                  ○                                                                          Δ                                                                           x                                            evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Sufficiently practically usable                                      x: Image defect formed                                                   

                                      TABLE 10C                                   __________________________________________________________________________    Sample No.                                                                            1401C                                                                             1402C                                                                             1403C                                                                             1404C                                                                             1405C                                                                             1406C                                                                             1407C                                                                             1408C                                     __________________________________________________________________________    SiH.sub.4 :C.sub.2 H.sub.4                                                            9:1 6:4 4:6 2:8 1:9 0.5:9.5                                                                           0.35:9.65                                                                         0.2:9.8                                   (flow rate ratio)                                                             Si:C    9:1 7:3 5.5:4.5                                                                           4:6 3:7 2:8 1.2:8.8                                                                           0.8:9.2                                   (content ratio)                                                               Image quality                                                                         Δ                                                                           ○                                                                          ⊚                                                                  ⊚                                                                  ⊚                                                                  ○                                                                          Δ                                                                           x                                         evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Sufficiently practically usable                                      x: Image defect formed                                                   

                                      TABLE 11C                                   __________________________________________________________________________    Sample No.                                                                            1501C                                                                             1502C                                                                              1503C                                                                             1504C                                                                             1505C                                                                              1506C                                                                              1507C 1508C                                __________________________________________________________________________    SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                 5:4:1                                                                             3:3.5:3.5                                                                          2:2:6                                                                             1:1:8                                                                             0.6:0.4:9                                                                          0.2:0.3:9.5                                                                        0.2:0.15:9.65                                                                       0.1:0.1:9.8                          (flow rate                                                                    ratio)                                                                        Si:C    9:1 7:3  5.5:4.5                                                                           4:6 3:7  2:8  1.2:8.8                                                                             0.8:9.2                              (content                                                                      ratio)                                                                        Image quality                                                                         Δ                                                                           ○                                                                           ⊚                                                                  ⊚                                                                  ⊚                                                                   ○                                                                           Δ                                                                             x                                    evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Practically satisfactory                                             x: Image defect formed                                                   

                  TABLE 12C                                                       ______________________________________                                        Sample                                                                              Thickness of                                                            No.   layer (II) (μ)                                                                        Results                                                      ______________________________________                                        1601C 0.001      Image defect liable to occur                                 1602C 0.02       No image defect during 20,000 repetitions                    1603C 0.05       Stable for 50,000 repetitions                                1604C 1          Stable for 200,000 repetitions                               ______________________________________                                    

                                      TABLE 1D                                    __________________________________________________________________________                                                  Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18   5    1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18  15    20                       layer                                                                    Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                         SiH.sub.4 /C.sub.2 H.sub.4 = 3/7                                                                0.18  10    0.5                          C.sub.2 H.sub.4                                                      __________________________________________________________________________

                                      TABLE 2D                                    __________________________________________________________________________                                                  Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =                                    3/10.sup.-3                                                B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 + SiH.sub.4 = 1/10                                                                    0.18  5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                      Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18  15    5                        layer                                                                    __________________________________________________________________________

                                      TABLE 3D                                    __________________________________________________________________________                                             Discharg-                                                                           Layer for-                                                                          Layer                    Layer    Gases    Flow rate              ing power                                                                           mation                                                                              thick-                   constitution                                                                           employed (SCCM)                                                                              Flow rate ratio  (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)               __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   GeH.sub.4 = 50                                                                      SiH.sub.4 /GeH.sub.4 = 1/100                                                                   0.18   5     2                            layer                                                                             GeH.sub.4 /He = 0.5                                                                          B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                              B.sub.2 H.sub.6 /He = 10.sup.-3                                                              NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                      NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                     B.sub.2 H.sub.6 /SiH.sub.4 = 2 × 10.sup.-4                                               0.18  15    20                            layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                  TABLE 4D                                                        ______________________________________                                        Sample No.                                                                             401D   302D   403D 404D 405D 506D 407D 408D                          ______________________________________                                        GeH.sub.4 /SiH.sub.4                                                                   5/100  1/10   2/10 4/10 5/10 7/10 8/10 1/1                           Flow rate                                                                     ratio                                                                         Ge content                                                                             4.3    8.4    15.4 26.7 32.3 38.9 42   47.6                          (atomic %)                                                                    Evaluation                                                                             ⊚                                                                     ⊚                                                                     ⊚                                                                   ⊚                                                                   ⊚                                                                   ○                                                                           ○                                                                           ○                      ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                         

                  TABLE 5D                                                        ______________________________________                                        Sample No.                                                                            501D   502D    503D 504D 505D 506D 507D 508D                          ______________________________________                                        Layer   30Å                                                                              500Å                                                                              0.1μ                                                                            0.3μ                                                                            0.8μ                                                                            3μ                                                                              4μ                                                                              5μ                         thickness                                                                     Evaluation                                                                            Δ                                                                              ○                                                                              ⊚                                                                   ⊚                                                                   ⊚                                                                   ○                                                                           ○                                                                           Δ                       ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                              Δ: Practically satisfactory                                        

                                      TABLE 6D                                    __________________________________________________________________________    (Sample No. 601D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 5/10                                                                    0.18   5     2                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         PH.sub.3 /SiH.sub.4 = 9 × 10.sup.-5                                                      0.18   15    20                       layer                                                                             PH.sub.3 /He = 10.sup.-3                                             Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                         SiH.sub.4 /C.sub.2 H.sub.4 = 3/7                                                               0.18   10    0.5                          C.sub.2 H.sub.4                                                      __________________________________________________________________________

                                      TABLE 7D                                    __________________________________________________________________________    (Sample No. 602D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     15                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 8                                  × 10.sup.-4                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         PH.sub.3 /SiH.sub.4 = 1 × 10.sup.-5                                                      0.18   15    5                        layer                                                                             PH.sub.3 /He = 10.sup.-3                                             Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 =  100                                                                        SiH.sub.4 /C.sub.2 H.sub.4 = 3/7                                                               0.18   10    0.5                          C.sub.2 H.sub.4                                                      __________________________________________________________________________

                                      TABLE 8D                                    __________________________________________________________________________    (Sample No. 603D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4        0.18   15    20                       layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub. 4 = 100                                                                        SiH.sub.4 /C.sub.2 H.sub.4 = 3/7                                                               0.18   10    0.5                          C.sub.2 H.sub.4                                                      __________________________________________________________________________

                                      TABLE 9D                                    __________________________________________________________________________    (Sample No. 701D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  ×  10.sup.-5                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4        0.18   15    5                        layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 10D                                   __________________________________________________________________________    (Sample No. 702D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /SiH.sub.4 = 3/100                                NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /SiH.sub.4 = 3/100                                NH.sub.3                                                                  Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 3/100                                                                    0.18   15    1                        layer                                                                             NH.sub.3           B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-4                                                  B.sub.2 H.sub.6 /He = 10.sup.-3                                           Fourth                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-4        0.18   15    15                       layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 11D                                   __________________________________________________________________________    (Sample No. 801D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜                                             NH.sub.3           2.83/100                                               Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              G.sub.2 H.sub.4 /SiH.sub.4 = 3/10                                                              0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4) =                        NH.sub.3           2.83/100˜0                                       Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200            0.18   5     19                       layer                                                                    __________________________________________________________________________     The flow rate ratio NH.sub.3 /(GeH.sub.4 + SiH.sub.4) was reduced             linearly.                                                                

                                      TABLE 12D                                   __________________________________________________________________________    (Sample No. 802D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     0.5                      layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He =  10.sup.-3                                                                 NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     0.5                      layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =  3                                 × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                      Fourth                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200            0.18   15    5                        layer                                                                    __________________________________________________________________________

                                      TABLE 13D                                   __________________________________________________________________________    (Sample No. 803D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                        layer                                                                             GiH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 1/100˜0                                            NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  ×  10.sup.-3                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 2 ×                                        10.sup.-4        0.18   15    20                       layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 14D                                   __________________________________________________________________________    (Sample No. 804D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer     Gases    Flow rate                 ing power                                                                            mation                                                                              thick-              constitution                                                                            employed (SCCM)     Flow rate ratio                                                                              (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                              SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 3/10                                                                  0.18   5     1                        layer                                                                              GeH.sub.4 /He = 0.05                                                                              B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-3                                                 B.sub.2 H.sub.6 /He = 10.sup.-3                                                                   NH.sub.3 /SiH.sub.4 = 3/100˜2.83/100                NH.sub.3                                                                 Second                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 = 200                                                                          NH.sub.3 /SiH.sub.4 = 2.83/100˜0                                                       0.18   15    20                       layer                                                                              NH.sub.3            B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4                                                 B.sub.2 H.sub.6 /He = 10.sup.-3                                     __________________________________________________________________________     The flow rate ratio NH.sub. 3 /SiH.sub.4 was reduced.                    

                                      TABLE 15D                                   __________________________________________________________________________    (Sample No. 805D)                                                                                                          Discharg-                                                                            Layer                                                                               Layer               Layer    Gases    Flow rate                  ing power                                                                            mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio  (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                    0.18   5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  ×  10.sup.-5                                         B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4        0.18   15    5                        layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________     The flow rate ratio NH.sub.3 /(GeH.sub.4 /SiH.sub.4) was reduced linearly

                                      TABLE 16D                                   __________________________________________________________________________          Gases   Flow rate Flow rate ratio                                                                         Discharging                                                                           Layer thick-                        Condition                                                                           employed                                                                              (SCCM)    or Area ratio                                                                           power (W/cm.sup.2)                                                                    ness(μ)                          __________________________________________________________________________    12-1D Ar      200       Si wafer:graphite =                                                                     0.3     0.5                                                         1.5:8.5                                               12-2D Ar      200       Si wafer:graphite =                                                                     0.3     0.3                                                         0.5:9.5                                               12-3D Ar      200       Si wafer: graphite =                                                                    0.3     1.0                                                         6:4                                                   12-4D SiH.sub.4 /He = 1                                                                     SiH.sub.4 = 15                                                                          SiH.sub.4 :C.sub.2 H.sub.4 =                                                            0.18    0.3                                       C.sub.2 H.sub.4   0.4:9.6                                               12-5D SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 = 100                                                                         SiH.sub.4 :C.sub.2 H.sub.4 =                                                            0.18    1.5                                       C.sub.2 H.sub.4   5:5                                                   12-6D SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 = 150                                                             SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                   0.18    0.5                                       SiF.sub.4 /He = 0.5                                                                             1.5:1.5:7                                                   C.sub.2 H.sub.4                                                         12-7D SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 =  15                                                             SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                   0.18    0.3                                       SiF.sub.4 /He = 0.5                                                                             0.3:0.1:9.6                                                 C.sub.2 H.sub.4                                                         12-8D SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 = 150                                                             SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                   0.18    1.5                                       SiF.sub.4 /He = 0.5                                                                             3:3:4                                                       C.sub.2 H.sub.4                                                         __________________________________________________________________________

                  TABLE 17D                                                       ______________________________________                                        Preparation                                                                   condition                                                                     for layer (II)                                                                           Sample No./Evaluation                                              ______________________________________                                        12-1D      12-401D     12-701D  12-801D                                                   ○   ○                                                                       ○   ○                                                                    ○   ○                          12-2D      12-402D     12-702D  12-802D                                                   ○   ○                                                                       ○   ○                                                                    ○   ○                          12-3D      12-403D     12-703D  12-803D                                                   ○   ○                                                                       ○   ○                                                                    ○   ○                          12-4D      12-404D     12-704D  12-804D                                                  ⊚ ⊚                                                         ⊚ ⊚                                                      ⊚ ⊚             12-5D      12-405D     12-705D  12-805D                                                  ⊚ ⊚                                                         ⊚ ⊚                                                      ⊚ ⊚             12-6D      12-406D     12-706D  12-806D                                                  ⊚ ⊚                                                         ⊚ ⊚                                                      ⊚ ⊚             12-7D      12-407D     12-707D  12-807D                                                   ○   ○                                                                       ○   ○                                                                    ○   ○                          12-8D      12-408D     12-708D  12-808D                                                   ○   ○                                                                       ○    ○                                                                   ○   ○                          ______________________________________                                        Sample No.                                                                    Overal image                                                                            Durability                                                          evaluation                                                                              evaluation                                                           Education standard:                                                           ⊚ Excellent                                                     ○  Good                                                          

                                      TABLE 18D                                   __________________________________________________________________________    Sample No.                                                                             1301D                                                                             1302D                                                                              1303D                                                                             1304D                                                                             1305D                                                                             1306D                                                                             1307D                                       __________________________________________________________________________    Si:C target                                                                            9:1 6.5:3.5                                                                            4:6 2:8 1:9 0.5:9.5                                                                           0.2:9.8                                     (area ratio)                                                                  Si:C     9.7:0.3                                                                           8.8:1.2                                                                            7.3:2.7                                                                           4.8:5.2                                                                           3:7 2:8 0.8:9.2                                     (content ratio)                                                               Image quality                                                                          Δ                                                                           ○                                                                           ⊚                                                                  ⊚                                                                  ○                                                                          Δ                                                                           x                                           evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Sufficiently practically usable                                      x: Image defect formed                                                   

                                      TABLE 19D                                   __________________________________________________________________________    Sample No.                                                                            1401D                                                                             1402D                                                                             1403D                                                                             1404D                                                                             1405D                                                                             1406D                                                                             1407D                                                                              1408D                                    __________________________________________________________________________    SiH.sub.4 :C.sub.2 H.sub.4                                                            9:1 6:4 4:6 2:8 1:9 0.5:9.5                                                                           0.35:9.65                                                                          0.2:9.8                                  (flow rate ratio)                                                             Si:C    9:1 7:3 5.5:4.5                                                                           4:6 3:7 2:8 1.2:8.8                                                                            0.8:9.2                                  (content ratio)                                                               Image quality                                                                         Δ                                                                           ○                                                                          ⊚                                                                  ⊚                                                                  ⊚                                                                  ○                                                                          Δ                                                                            x                                        evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Sufficiently practically usable                                      x: Image defect formed                                                   

                                      TABLE 20D                                   __________________________________________________________________________    Sample No.                                                                            1501D                                                                             1502D                                                                              1503D                                                                             1504D                                                                             1505D                                                                              1506D 1507D  1508D                              __________________________________________________________________________    SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4                                                 5:4:1                                                                             3:3.5:3.5                                                                          2:2:6                                                                             1:1:8                                                                             0.6:0.4:9                                                                          0.2:0.3:9.5                                                                         0.2:0.15:9.65                                                                        0.1:0.1:9.8                        (flow rate                                                                    ratio)                                                                        Si:C    9:1 7:3  5.5:4.5                                                                           4:6 3:7  2:8   1.2:8.8                                                                              0.8:9.2                            (content                                                                      ratio)                                                                        Image quality                                                                         Δ                                                                           ○                                                                           ⊚                                                                  ⊚                                                                  ⊚                                                                   ○                                                                            Δ                                                                              x                                  evaluation                                                                    __________________________________________________________________________     ⊚: very good                                                    ○ : Good                                                              Δ: Practically satisfactory                                             x: Image defect formed                                                   

                  TABLE 21D                                                       ______________________________________                                                 Thickness of                                                         Sample No.                                                                             layer (II) (μ)                                                                         Results                                                  ______________________________________                                        1601D    0.001       Image defect liable to occur                             1602D    0.02        No image defect during 20,000                                                 repetitions                                              1603D    0.05        Stable for 50,000 repetitions                            1604D    1           Stable for 200,000 repetitions                           ______________________________________                                    

                                      TABLE 1E                                    __________________________________________________________________________                                                 Discharg-                                                                            Layer                                                                               Layer               Layer     Gases    Flow rate                 ing power                                                                            mation                                                                              thick-              constitution                                                                            employed (SCCM)     Flow rate ratio                                                                              (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                              SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 1/1                                                                   0.18   5     3                        layer                                                                              GeH.sub.4 /He = 0.05                                                                              NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                 NH.sub.3                                                                 Second                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200           0.18   15    15                       layer                                                                    Layer (II)                                                                              SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                          SiH.sub.4 /NO = 1                                                                            0.18   10    0.5                           NO                                                                  __________________________________________________________________________

                                      TABLE 2E                                    __________________________________________________________________________                                                 Discharg-                                                                            Layer                                                                               Layer               Layer     Gases    Flow rate                 ing power                                                                            mation                                                                              thick-              constitution                                                                            employed (SCCM)    Flow rate ratio (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                              SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                   0.18   5     5                        layer                                                                              GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3           (linearly reduced)                                    Second                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                   0.18   5     1                        layer                                                                              GeH.sub.4 /He = 0.05                                                     Third                                                                              SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200           0.18   15    15                       layer                                                                    __________________________________________________________________________

                                      TABLE 3E                                    __________________________________________________________________________                                        Discharg-                                                                           Layer for-                                                                          Layer                         Layer    Gases    Flow rate         ing power                                                                           mation                                                                              thick-                        constitution                                                                           employed (SCCM)                                                                              Flow rate ratio                                                                           (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ)                    __________________________________________________________________________    Layer (I)                                                                          First                                                                             GeH.sub.4 /He = 0.5                                                                    GeH.sub.4 = 50                                                                      NH.sub.3 /GeH.sub.4 = 2/100                                                               0.18  5     2                                  layer                                                                             NH.sub.3                                                                      B.sub.2 H.sub.6 /He = 10.sup.-3                                           Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                     NH.sub.3 /SiH.sub.4 = 2/100                                                               0.18  15    2                                  layer                                                                             NH.sub.3       B.sub.2 H.sub.6 /SiH.sub.4 = 1 × 10.sup.-5           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                     B.sub.2 H.sub.6 /SiH.sub.4 = 1 × 10.sup.-5                                          0.18  15    15                                 layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                  TABLE 4E                                                        ______________________________________                                        Sample No.                                                                            401E    402E   403E  404E 405E  406E 407E                             ______________________________________                                        Ge content                                                                            1       3      5     10   40    60   90                               (atomic %)                                                                    Evaluation                                                                            Δ ○                                                                             ⊚                                                                    ⊚                                                                   ⊚                                                                    ○                                                                           Δ                          ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                              Δ: Practically satisfactory                                        

                  TABLE 5E                                                        ______________________________________                                        Sample No.   501E    502E    503E  504E  505E                                 ______________________________________                                        Layer thickness(μ)                                                                      0.1     0.5     1     2     5                                    Evaluation   ○                                                                              ○                                                                              ⊚                                                                    ⊚                                                                    ○                             ______________________________________                                         ⊚: Excellent                                                    ○ : Good                                                         

                                      TABLE 6E                                    __________________________________________________________________________                                                 Discharg-                                                                            Layer                                                                               Layer               Layer     Gases    Flow rate                 ing power                                                                            mation                                                                              thick-              constitution                                                                            employed (SCCM)     Flow rate ratio                                                                              (W/cm.sup.2)                                                                         (Å/sec)                                                                         ness(μ)          __________________________________________________________________________    Layer (I)                                                                          First                                                                              SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 4/10                                                                  0.18   5     2                        layer                                                                              GeH.sub.4 /He = 0.05                                                                              NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 2/100                 NH.sub.3                                                                 Second                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                          PH.sub.3 /SiH.sub.4 = 1 × 10.sup.-7                                                    0.18   15    20                            PH.sub.3 /He = 10.sup.-3                                            Layer (II)                                                                              SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                          SiH.sub.4 /NO = 1                                                                            0.15   10    0.5                           NO                                                                  __________________________________________________________________________

                                      TABLE 7E                                    __________________________________________________________________________          Gases   Flow rate Flow rate ratio                                                                        Discharging                                                                           Layer thick-                         Conditions                                                                          employed                                                                              (SCCM)    or Area ratio                                                                          power (W/cm.sup.2)                                                                    ness(μ)                           __________________________________________________________________________    11-1E Ar (NO/Ar)                                                                            200 (1/1) Si wafer:SiO.sub.2 =                                                                   0.3     0.5                                                          1:30                                                  11-2E Ar (NO/Ar)                                                                            200 (1/1) Si wafer:SiO.sub.2 =                                                                   0.3     0.3                                                          1:60                                                  11-3E Ar (NO/Ar)                                                                            200 (1/1) Si wafer:SiO.sub.2 =                                                                   0.3     1.0                                                          6:4                                                   11-4E SiH.sub.4 /He = 1                                                                     SiH.sub.4 = 15                                                                          SiH.sub.4 :NO =                                                                        0.18    0.3                                        NO                5:1                                                   11-5E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 = 100                                                                         SiH.sub.4 :NO =                                                                        0.18    1.5                                        NO                1:1                                                   11-6E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 =                                                                 SiH.sub.4 :SiF.sub.4 :NO =                                                             0.18    0.5                                        SiF.sub.4 /He = 0.5                                                                   150       1:1:1                                                       NO                                                                      11-7E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 = 15                                                              SiH.sub.4 :SiF.sub.4 :NO =                                                             0.18    0.3                                        SiF.sub.4 /He = 0.5                                                                             2:1:4                                                       NO                                                                      11-8E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 =                                                                 SiH.sub.4 :SiF.sub.4 :NO                                                               0.18    1.5                                        SiF.sub.4 /He = 0.5                                                                   150       1:1:3                                                       NO                                                                      __________________________________________________________________________

                  TABLE 8E                                                        ______________________________________                                        Preparation                                                                   condition                                                                     for layer (II)                                                                           Sample No./Evaluation                                              ______________________________________                                        11-1E      11-201E     11-301E   11-601E                                                  ○   ○                                                                       ○  ○   ○                         11-2E      11-202E     11-302E   11-602E                                                  ○   ○                                                                       ○  ○   ○                         11-3E      11-203E     11-303E   11-603E                                                  ○   ○                                                                       ○  ○   ○                         11-4E      11-204E     11-304E   11-604E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-5E      11-205E     11-305E   11-605E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-6E      11-206E     11-306E   11-606E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-7E      11-207E     11-307E   11-607E                                                  ○   ○                                                                       ○  ○   ○                         11-8E      11-208E     11-308E   11-608E                                                  ○   ○                                                                       ○  ○   ○                         ______________________________________                                        Sample No.                                                                    Overal image                                                                            Durability                                                          evaluation                                                                              evaluation                                                           Education standard:                                                           ⊚ Excellent                                                     ○  Good                                                          

                                      TABLE 9E                                    __________________________________________________________________________    Sample No.                                                                              1201E                                                                             1202E                                                                             1203E                                                                             1204E                                                                             1205E                                                                             1206E                                                                             1207E                                       __________________________________________________________________________    Si:SiO.sub.2                                                                            9:1 6.5:3.5                                                                            4:10                                                                              2:20                                                                              1:100                                                                             1.100                                                                             1.100                                      target (area ratio)                                                                     (0/1)                                                                             (1/1)                                                                             (1/1)                                                                             (1/1)                                                                             (2/1)                                                                             (3/1)                                                                             (4/1)                                       (NO/Ar)                                                                       Si:O      9.7:0.3                                                                           8.8:1.2                                                                           7.3:2.7                                                                           5.0:5.0                                                                           4.5:5.5                                                                           4:6 3:7                                         (content ratio)                                                               Image quality                                                                           Δ                                                                           ⊚                                                                  ⊚                                                                  ○                                                                          ○                                                                          Δ                                                                           x                                           evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Sufficiently practically usable                                      x: Image defect formed                                                   

                                      TABLE 10E                                   __________________________________________________________________________    Sample No.                                                                            1301E  1302E                                                                             1303E                                                                            1304E                                                                             1305E                                                                            1306E                                                                             1307E                                        __________________________________________________________________________    SiH.sub.4 :NO                                                                         1000:1 99:1                                                                              5:1                                                                              1:1 1:2                                                                              3:10                                                                                1:1000                                     (Flow rate                                                                    ratio)                                                                        Si:O    9.9999:0.0001                                                                        9.9:01                                                                            9:1                                                                              6:4 5:5                                                                              3.3:6.7                                                                           2:8                                          (content                                                                      ratio)                                                                        Image quality                                                                         Δ                                                                              ○                                                                          ⊚                                                                 ⊚                                                                  ○                                                                         Δ                                                                           x                                            evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Practically satisfactory                                             x: Image defect formed                                                   

                                      TABLE 11E                                   __________________________________________________________________________    Sample No.                                                                            1401E  1402E                                                                             1403E                                                                             1404E                                                                             1405E                                                                             1406E                                                                             1407E                                      __________________________________________________________________________    SiH.sub.4 :SiF.sub.4 :NO                                                              500:400:1                                                                            50:50:1                                                                           5:5:2                                                                             5:5:10                                                                            1:1:4                                                                             3:3:20                                                                            1:1:2000                                   (Flow rate ratio)                                                             Si:O    9.9998:0.0002                                                                        9.8:0.2                                                                           8.8:1.2                                                                           6.3:3.7                                                                           5.1:4.9                                                                           3.5:6.5                                                                           2.3:7.7                                    (content ratio)                                                               Image quality                                                                         Δ                                                                              ○                                                                          ⊚                                                                  ⊚                                                                  ○                                                                          x   Δ                                    evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Practically satisfactory                                             x: Image defect formed                                                   

                  TABLE 12E                                                       ______________________________________                                                  Thickness of                                                        Sample No.                                                                              second layer (II)                                                                            Results                                              ______________________________________                                        1601E     0.001          Image defect liable                                                           to occur                                             1602E     0.02           No image defect                                                               during 20,000                                                                 repetitions                                          1603E     0.05           Stable for 50,000                                                             repetitions                                          1604E     1              Stable for 200,000                                                            repetitions                                          ______________________________________                                    

                                      TABLE 1F                                    __________________________________________________________________________                                                  Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18   5    1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18  15    20                       layer                                                                    Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                         SiH.sub.4 /NO = 1 0.18  10    0.5                          NO                                                                   __________________________________________________________________________

                                      TABLE 2F                                    __________________________________________________________________________                                                  Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 + SiH.sub.4 = 1/10                                                                    0.18  5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                      Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18  15    5                        layer                                                                    __________________________________________________________________________

                                      TABLE 3F                                    __________________________________________________________________________                                        Discharg-                                                                           Layer for-                                                                          Layer                         Layer    Gases    Flow rate         ing power                                                                           mation                                                                              thick-                        constitution                                                                           employed (SCCM)                                                                              Flow rate ratio                                                                           (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ                     __________________________________________________________________________                                                    )                             Layer (I)                                                                          First                                                                             GeH.sub.4 /He = 0.05                                                                   GeH.sub.4 = 50                                                                      B.sub.2 H.sub.6 /GeH.sub.4 = 5 × 10.sup.-3                                          0.18   5     2                                 layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                                              NH.sub.3 /GeH.sub.4 = 1/100                                    NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                     B.sub.2 H.sub.6 /SiH.sub.4 = 2 × 10.sup.-4                                          0.18  15    20                                 layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 4F                                    __________________________________________________________________________    Sample No.                                                                              401E                                                                              402E                                                                             403E                                                                             404E                                                                              405E                                                                             406E                                                                             407E                                                                             408E                                         __________________________________________________________________________    GeH.sub.4 + SiH.sub.4                                                                   5/100                                                                             1/10                                                                             2/10                                                                             4/10                                                                              5/10                                                                             7/10                                                                             8/10                                                                             1/1                                          (Flow rate ratio)                                                             Ge content                                                                              4.3 8.4                                                                              15.4                                                                             26.7                                                                              32.2                                                                             38.9                                                                             42 47.6                                         (atomic %)                                                                    Evaluation                                                                              ⊚                                                                  ⊚                                                                 ⊚                                                                 ⊚                                                                  ⊚                                                                 ○                                                                         ○                                                                         ○                                     __________________________________________________________________________     ⊚: Excellent                                                    ○ : Good                                                         

                                      TABLE 5F                                    __________________________________________________________________________    Sample No.                                                                              501E                                                                             502E                                                                              503E                                                                             504E                                                                              505E                                                                             506E                                                                             507E                                                                             508E                                         __________________________________________________________________________    Layer thickness(μ )                                                                  30Å                                                                          500Å                                                                          0.1μ                                                                          0.3μ                                                                           0.8μ                                                                          3μ                                                                            4μ                                                                            5μ                                        Evaluation                                                                              Δ                                                                          ○                                                                          ⊚                                                                 ⊚                                                                  ⊚                                                                 ○                                                                         ○                                                                         Δ                                      __________________________________________________________________________     ⊚: Excellent                                                    ○ : Good                                                              Δ: Practically satisfactory                                        

                                      TABLE 6F                                    __________________________________________________________________________    (Sample No. 601F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 5/10                                                                     0.18   5    2                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         PH.sub.3 /SiH.sub.4 = 9 × 10.sup.-5                                                       0.18  15    20                       layer                                                                             PH.sub.3 /He = 10.sup.-3                                             Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 SiH.sub.4 /NO = 1 0.18  10    0.5                          NO                                                                   __________________________________________________________________________

                                      TABLE 7F                                    __________________________________________________________________________    (Sample No. 602F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18   5    15                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 8                                  × 10.sup.-4                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 1/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         PH.sub.3 /SiH.sub.4 = 1 × 10.sup.-5                                                       0.18  15    5                        layer                                                                             PH.sub.3 /He = 10.sup.-3                                             Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 SiH.sub.4 /NO = 1 0.18  10    0.5                          NO                                                                   __________________________________________________________________________

                                      TABLE 8F                                    __________________________________________________________________________    (Sample No. 603F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18   5    1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4         0.18  15    20                       layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      Layer (II)                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 100                                                                         SiH.sub.4 /NO = 1 0.18  10    0.5                          NO                                                                   __________________________________________________________________________

                                      TABLE 9F                                    __________________________________________________________________________    (Sample No. 701F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 3/100                  NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =  1                                 × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4         0.18  15    5                        layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 10F                                   __________________________________________________________________________    (Sample No. 702F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         nes(μ            __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18   5    1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /SiH.sub.4 = 3/100                                NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18   5    1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /SiH.sub.4 = 3/100                                NH.sub.3                                                                  Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 3/100                                                                     0.18  15    1                        layer                                                                             NH.sub.3           B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-4                                                  B.sub.2 H.sub.6 /He = 10.sup.-3                                           Fourth                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 1 ×                                        10.sup.-4         0.18  15    15                       layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 11F                                   __________________________________________________________________________    (Sample No. 801F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜                                             NH.sub.3           2.83/100                                               Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             NH.sub.3 /(GeH.sub.4 + SiH.sub.4) =                        NH.sub.3           2.83/100˜0                                       Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18  15    19                       layer                                                                    __________________________________________________________________________     The flow rate ratio NH.sub.3 /(GeH.sub.4 + SiH.sub.4) was reduced             linearly.                                                                

                                      TABLE 12F                                   __________________________________________________________________________    (Sample No. 802F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     0.5                      layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     0.5                      layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 3                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                      Fourth                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200             0.18  15    5                        layer                                                                    __________________________________________________________________________

                                      TABLE 13F                                   __________________________________________________________________________    (Sample No. 803F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 +GeH.sub.4 = 50                                                               GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 1/100˜0                                            NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 5                                  × 10.sup.-3                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 2 ×                                        10.sup.-4         0.18  15    20                       layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________

                                      TABLE 14F                                   __________________________________________________________________________    (Sample No. 804F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness                __________________________________________________________________________                                                              (μ)              Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 3/10                                                                     0.18   5     1                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-3                                                  B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /SiH.sub.4 = 3/100˜2.83/100                 NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         NH.sub.3 /SiH.sub.4 = 2.83/100˜0                                                          0.18  15    20                       layer                                                                             NH.sub.3           B.sub.2 H.sub.6 SiH.sub.4 = 3 ×                                         10.sup.-4                                                  B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________     The flow rate ratio NH.sub.3 /SiH.sub.4 was reduced linearly.            

                                      TABLE 15F                                   __________________________________________________________________________    (Sample No. 805F)                                                                                                           Discharg-                                                                           Layer                                                                               Layer               Layer    Gases    Flow rate                   ing power                                                                           mation                                                                              thick-              constitution                                                                           employed (SCCM)    Flow rate ratio   (W/cm.sup.2)                                                                        (Å/sec)                                                                         ness(μ           __________________________________________________________________________                                                              )                   Layer (I)                                                                          First                                                                             SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.4 /SiH.sub.4 = 1/10                                                                     0.18  5     1                        layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 1                                  × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                                                  NH.sub.3 /(GeH.sub.4 + SiH.sub.4)                                             = 3/100˜0                                            NH.sub.3                                                                  Second                                                                            SiH.sub.4 /He = 0.05                                                                   SiH.sub.4 + GeH.sub.4 = 50                                                              GeH.sub.2 /SiH.sub.4 = 1/10                                                                     0.18  5     19                       layer                                                                             GeH.sub.4 /He = 0.05                                                                             B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) =  1                                 × 10.sup.-5                                          B.sub.2 H.sub.6 /He = 10.sup.-3                                           Third                                                                             SiH.sub.4 /He = 0.5                                                                    SiH.sub.4 = 200                                                                         B.sub.2 H.sub.6 /SiH.sub.4 = 3 ×                                        10.sup.-4         0.18  15    5                        layer                                                                             B.sub.2 H.sub.6 /He = 10.sup.-3                                      __________________________________________________________________________     The flow rate ratio NH.sub.3 /(GeH.sub.4 /SiH.sub.4) was reduced linearly

                                      TABLE 16F                                   __________________________________________________________________________          Gases   Flow rate Flow rate ratio                                                                        Discharging                                                                           Layer thick-                         Conditions                                                                          employed                                                                              (SCCM)    or Area ratio                                                                          power (W/cm.sup.2)                                                                    ness(μ )                          __________________________________________________________________________    11-1E Ar (NO/Ar)                                                                            200 (1/1) Si wafer:SiO.sub.2 =                                                                   0.3     0.5                                                          1:30                                                  11-2E Ar (NO/Ar)                                                                            200 (1/1) Si wafer:SiO.sub.2 =                                                                   0.3     0.3                                                          1:60                                                  11-3E Ar (NO/Ar)                                                                            200 (1/1) Si wafer:SiO.sub.2 =                                                                   0.3     1.0                                                          6:4                                                   11-4E SiH.sub.4 /He = 1                                                                     SiH.sub.4 = 15                                                                          SiH.sub.4 :NO =                                                                        0.18    0.3                                        NO                5:1                                                   11-5E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 = 100                                                                         SiH.sub.4 :NO =                                                                        0.18    1.5                                        NO                1:1                                                   11-6E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 =                                                                 SiH.sub.4 :SiF.sub.4 :NO =                                                             0.18    0.5                                        SiF.sub.4 /He = 0.5                                                                   150       1:1:1                                                       NO                                                                      11-7E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 = 15                                                              SiH.sub.4 :SiF.sub.4 :NO =                                                             0.18    0.3                                        SiF.sub.4 /He = 0.5                                                                             2:1:4                                                       NO                                                                      11-8E SiH.sub.4 /He = 0.5                                                                   SiH.sub.4 + SiF.sub.4 =                                                                 SiH.sub.4 :SiF.sub.4 :NO =                                                             0.18    1.5                                        SiF.sub.4 /He = 0.5                                                                   150       1:1:3                                                       NO                                                                      __________________________________________________________________________

                  TABLE 17F                                                       ______________________________________                                        Preparation                                                                   condition                                                                     for layer (II)                                                                           Sample No./Evaluation                                              ______________________________________                                        11-1E      11-101E     11-201E   11-301E                                                  ○   ○                                                                       ○ ○ ○                            11-2E      11-102E     11-202E   11-302E                                                  ○   ○                                                                       ○ ○ ○                            11-3E      11-103E     11-203E   11-303E                                                  ○   ○                                                                       ○ ○ ○                            11-4E      11-104E     11-204E   11-304E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-5E      11-105E     11-205E   11-305E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-6E      11-106E     11-206E   11-306E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-7E      11-107E     11-207E   11-307E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            11-8E      11-108E     11-208E   11-308E                                                 ⊚ ⊚                                                         ⊚ ⊚                                                       ⊚ ⊚            ______________________________________                                        Sample No.                                                                    Overall image                                                                           Durability                                                          evaluation                                                                              evaluation                                                           Education standard:                                                           ⊚: Excellent                                                    ○ : Good                                                         

                                      TABLE 18F                                   __________________________________________________________________________    Sample No.                                                                             1201E                                                                              1202E                                                                             1203E                                                                            1204E                                                                             1205E                                                                              1206E                                                                             1207E                                       __________________________________________________________________________    Si:SiO.sub.2                                                                           9:1  6.5:3.5                                                                            4:10                                                                             2:20                                                                              1:100                                                                             1:100                                                                             1:100                                       target (area ratio)                                                                    (0/1)                                                                              (1/1)                                                                             (1/1)                                                                            (1/1)                                                                             (2/1)                                                                              (3/1)                                                                             (4/1)                                       (NO/Ar)                                                                       Si:O     9.7:0.3                                                                            8.8:1.2                                                                           7.3:2.7                                                                          5.0:5.0                                                                           4.5:5.5                                                                            4:6 3:7                                         (content ratio)                                                               Image quality                                                                          Δ                                                                            ⊚                                                                  ⊚                                                                 ○                                                                          ○                                                                           Δ                                                                           x                                           evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Sufficiently practically usable                                      x: Image defect formed                                                   

                                      TABLE 19F                                   __________________________________________________________________________    Sample No.                                                                           1301E  1302E                                                                             1303E                                                                             1304E                                                                             1305E                                                                             1306E                                                                             1307E                                       __________________________________________________________________________    SiH.sub.4 :NO                                                                        1000:1 99:1                                                                              5:1 1:1 1:2  3:10                                                                             1:1000                                      (Flow rate                                                                    ratio)                                                                        Si:O   9.9999:0.0002                                                                        9.9:0.1                                                                           9:1 6:4 5:5 3.3:6.7                                                                           2:8                                         (content                                                                      ratio)                                                                        Image quality                                                                        Δ                                                                              ○                                                                          ⊚                                                                  ⊚                                                                  ○                                                                          Δ                                                                           x                                           evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Practically satisfactory                                             x: Image defect formed                                                   

                                      TABLE 20F                                   __________________________________________________________________________    Sample No.                                                                            1401E  1402E                                                                             1403E                                                                             1404E                                                                             1405E                                                                             1406E                                                                             1407E                                      __________________________________________________________________________    SiH.sub.4 :SiF.sub.4 :NO                                                              500:400:1                                                                            50:50:1                                                                           5:5:2                                                                             5:5:10                                                                              1:1:4                                                                           3:3:20                                                                            1:1:2000                                   (flow rate ratio)                                                             Si:O    9.9998:0.0002                                                                        9.8:0.2                                                                           8.8:1.2                                                                           6.3:3.7                                                                           5.1:4.9                                                                           3.5:6.5                                                                           2.3:7.7                                    (content ratio)                                                               Image quality                                                                         Δ                                                                              ○                                                                          ⊚                                                                  ⊚                                                                  ○                                                                          x   Δ                                    evaluation                                                                    __________________________________________________________________________     ⊚: Very good                                                    ○ : Good                                                              Δ: Practically satisfactory                                             x: Image defect formed                                                   

                  TABLE 21F                                                       ______________________________________                                                  Thickness                                                           Sample No.                                                                              of layer (II)  Results                                              ______________________________________                                        1601E     0.001          Image defect liable to                                                        occur                                                1602E     0.02           No image defect during                                                        20,000 repetitions                                   1603E     0.05           Stable for 50,000                                                             repetitions                                          1604E     1              Stable for 200,000                                                            repetitions                                          ______________________________________                                    

What we claim is:
 1. A photoconductive member comprising a substrate forphotoconductive member and a light receiving layer provided on saidsubstrate having a layer constitution in which a first layer region (G)comprising an amorphous material containing germanium atoms and at leastone of hydrogen atoms and halogen atoms, and a second layer region (S)exhibiting photoconductivity comprising an amorphous material containingsilicon atoms and at least one of hydrogen atoms and halogen atoms, aresuccessively provided from the substrate side, said light receivinglayer containing nitrogen atoms.
 2. A photoconductive member accordingto claim 1, wherein hydrogen atoms are contained in at least one of thefirst layer region (G) and the second layer region (S).
 3. Aphotoconductive member according to claim 1, wherein halogen atoms arecontained in at least one of the first layer region (G) and the secondlayer region (S).
 4. A photoconductive member according to claim 1,wherein the amount of germanium atoms contained in the first layerregion (G) is 1 to 1×10⁶ atomic ppm based on the sum with silicon atomsin the first layer region (G).
 5. A photoconductive member according toclaim 1, wherein the first layer region (G) has a layer thickness T_(B)of 30 Å to 50μ.
 6. A photoconductive member according to claim 1,wherein the second layer region (S) has a layer thickness T of 0.5 to90μ.
 7. A photoconductive member according to claim 1, wherein there isthe relationship between the layer thickness T_(B) of the first layerregion (G) and the layer thickness T of the second layer region (S) ofT_(B) /T≦1.
 8. A photoconductive member according to claim 1, whereinthe layer thickness T_(B) of the first layer region (G) is 30μ or less,when the content of germanium atoms contained in the first layer region(G) is 1×105 atomic ppm or more based on the sum with silicon atoms inthe first layer region (G).
 9. A photoconductive member according toclaim 1, wherein the content of nitrogen atoms in the layer region (N)in which nitrogen atoms are to be contained is 0.001 to 50 atomic %. 10.A photoconductive member according to claim 1, wherein nitrogen atomsare contained in the light receiving layer in such a state that nitrogenatoms are distributed in the layer region (N) in which nitrogen atomsare to be contained ununiformly in its layer thickness direction.
 11. Aphotoconductive member according to claim 1, wherein a substance (C) forcontrolling conductivity is contained in the light receiving layer. 12.A photoconductive member according to claim 11, wherein the substance(C) for controlling conductivity is an atom belonging to the group IIIof the periodic table.
 13. A photoconductive member according to claim12, wherein the atom belonging to the group III of the periodic table isselected from among B, Al, Ga, In and Tl.
 14. A photoconductive memberaccording to claim 11, wherein the substance (C) for controllingconductivity is an atom belonging to the group V of the periodic table.15. A photoconductive member according to claim 14, wherein the atombelonging to the group V of the periodic table is selected from among P,As, Sb and Bi.
 16. A photoconductive member according to claim 11,wherein the content of the substance (C) for controlling conductivity inthe light receiving layer is 0.01 to 5×10⁴ atomic ppm.
 17. Aphotoconductive member according to claim 1, wherein a substance (C) forcontrolling conductivity is contained in the first layer region (G). 18.A photoconductive member according to claim 17, wherein the content ofthe substance (C) for controlling conductivity in the first layer region(G) is 0.01 to 5×10⁴ atomic ppm.
 19. A photoconductive member accordingto claim 1, wherein a substance (C) for controlling conductivity iscontained in the second layer region (S).
 20. A photoconductive memberaccording to claim 19, wherein the content of the substance (C) forcontrolling conductivity in the second layer region (S) is 0.001 to 1000atomic ppm.
 21. A photoconductive member according to claim 1, wherein0.01 to 40 atomic % of hydrogen atoms are contained in the first layerregion (G).
 22. A photoconductive member according to claim 1, wherein0.01 to 40 atomic % of halogen atoms are contained in the first layerregion (G).
 23. A photoconductive member according to claim 1, wherein0.01 to 40 atomic % as the total of hydrogen atoms and halogen atoms arecontained in the first layer region (G).
 24. A photoconductive memberaccording to claim 1, wherein 1 to 40 atomic % of hydrogen atoms arecontained in the second layer region (S).
 25. A photoconductive memberaccording to claim 1, wherein 1 to 40 atomic % of halogen atoms arecontained in the second layer region (S).
 26. A photoconductive memberaccording to claim 1, wherein 1 to 40 atomic % as total of hydrogenatoms and halogen atoms are contained in the second layer region (S).27. A photoconductive member according to claim 1, wherein the lightreceiving layer has a layer region (PN) containing a substance (C) forcontrolling conductivity.
 28. A photoconductive member according toclaim 27, wherein the layer region (PN) is provided is the end portionlayer region on the substrate side of the light receiving layer.
 29. Aphotoconductive member according to claim 27, wherein the layer region(PN) has the bonded interface between the first layer region (G) and thesecond layer region (S) in its inner portion.
 30. A photoconductivemember according to claim 27, wherein the layer region (PN) is providedin the second layer region (S).
 31. A photoconductive member accordingto claim 27, wherein the layer region (PN) is provided in the layerregion (G).
 32. A photoconductive member according to claim 27, whereinthe content of the substance (C) for controlling conductivity in thelayer region (PN) is 0.01 to 5×10⁴ atomic ppm.
 33. A photoconductivemember comprising a substrate for photoconductive member and a lightreceiving layer provided on said substrate consisting of a first layer(I) with a layer constitution in which a first layer region (G)comprising an amorphous material containing germanium atoms and at leastone of hydrogen atoms and halogen atoms, and a second layer region (S)exhibiting photoconductivity comprising an amorphous material containingsilicon atoms and at least one of hydrogen atoms and halogen atoms, aresuccessively provided from the substrate side and a second layer (II)comprising an amorphous material containing silicon atoms and at leastone of carbon atoms and oxygen atoms, said first layer (I) containingnitrogen atoms therein.
 34. A photoconductive member according to claim33, wherein hydrogen atoms are contained in at least one of the firstlayer region (G) and the second layer region (S).
 35. A photoconductivemember according to claim 33, wherein halogen atoms are contained in atleast one of the first layer region (G) and the second layer region (S).36. A photoconductive member according to claim 33, wherein the amountof germanium atoms contained in the first layer region (G) is 1 to 1×10⁶atomic ppm based on the sum with shown silicon atoms in the first layerregion (G).
 37. A photoconductive member according to claim 33, whereinthe first layer region (G) has a layer thickness T_(B) of 30 Å to 50μ.38. A photoconductive member according to claim 33, wherein the secondlayer region (S) has layer thickness T of 0.5 to 90μ.
 39. Aphotoconductive member according to claim 33, wherein there is therelationship between the layer thickness T_(B) of the first layer region(G) and the layer thickness T of the second layer region (S) of T_(B)/T≦1.
 40. A photoconductive member according to claim 33, wherein thelayer thickness T_(B) of the first layer region (G) is 30μ or less, whenthe content of germanium atoms contained in the first layer region (G)is 1×10⁵ atomic ppm or more based on the sum with silicon atoms in thefirst layer region (G).
 41. A photoconductive member according to claim33, wherein the content of nitrogen atoms in the layer region (N) inwhich nitrogen atoms are to be contained is 0.001 to 50 atomic %.
 42. Aphotoconductive member according to claim 33, wherein nitrogen atoms arecontained in the first layer (I) in such a state that nitrogen atoms aredistributed in the layer region (N) in which nitrogen atoms are to becontained ununiformly in its layer thickness direction.
 43. Aphotoconductive member according to claim 33, wherein a substance (C)for controlling conductivity is contained in the first layer (I).
 44. Aphotoconductive member according to claim 43, wherein the substance (C)for controlling conductivity is an atom belonging to the group III ofthe periodic table.
 45. A photoconductive member according to claim 44,wherein the atom belonging to the group III of the periodic table isselected from among B, Al, Ga, In and Tl.
 46. A photoconductive memberaccording to claim 43, wherein the substance (C) for controllingconductivity is an atom belonging to the group V of the periodic table.47. A photoconductive member according to claim 46, wherein the atombelonging to the group V of the periodic table is selected from among P,As, Sb and Bi.
 48. A photoconductive member according to claim 43,wherein the content of the substance (C) for controlling conductivity inthe first layer (I) is 0.01 to 5×10⁴ atomic ppm.
 49. A photoconductivemember according to claim 33, wherein a substance (C) for controllingconductivity is contained in the first layer region (G).
 50. Aphotoconductive member according to claim 49, wherein the content of thesubstance (C) for controlling conductivity in the first layer region (G)is 0.01 to 5×10⁴ atomic ppm.
 51. A photoconductive member according toclaim 3, wherein a substance (C) for controlling conductivity iscontained in the second layer region (S).
 52. A photoconductive memberaccording to claim 1, wherein the content of the substance (C) forcontrolling conductivity in the second layer region (S) is 0.001 to 1000atomic ppm.
 53. A photoconductive member according to claim 33, wherein0.01 to 40 atomic % of hydrogen atoms are contained in the first layerregion (G).
 54. A photoconductive member according to claim 33, wherein0.01 to 40 atomic % of halogen atoms are contained in the first layerregion (G).
 55. A photoconductive member according to claim 33, wherein0.01 to 40 atomic % as the total of hydrogen atoms and halogen atoms arecontained in the first layer region (G).
 56. A photoconductive memberaccording to claim 33, wherein 1 to 40 atomic % of hydrogen atoms arecontained in the second layer region (S).
 57. A photoconductive memberaccording to claim 33, wherein 1 to 40 atomic % of halogen atoms arecontained in the second layer region (S).
 58. A photoconductive memberaccording to claim 33, wherein 1 to 40 atomic % as the total of hydrogenatoms and halogen atoms are contained in the second layer region (S).59. A photoconductive member according to claim 33, wherein the firstlayer (I) has a layer region (PN) containing a substance (C) forcontrolling conductivity.
 60. A photoconductive member according toclaim 59, wherein the layer region (PN) is provided as the end portionlayer region on the substrate side of the light receiving layer.
 61. Aphotoconductive member according to claim 59, wherein the layer region(PN) has the bonded interface between the first layer region (G) and thesecond layer region (S) in its inner portion.
 62. A photoconductivemember according to claim 59, wherein the layer region (PN) is providedin the second layer region (S).
 63. A photoconductive member accordingto claim 59, wherein the layer region (PN) is provided in the layerregion (G).
 64. A photoconductive member according to claim 59, whereinthe content of the substance (C) for controlling conductivity in thelayer region (PN) is 0.01 to 5×10⁴ atomic ppm.
 65. A photoconductivemember according to claim 33, wherein the amorphous materialconstituting the second layer (II) is an amorphous material representedby the following formula:

    a-(Si.sub.x C.sub.1-x).sub.y (H,X).sub.1-y

(where 0<x, y<1).
 66. A photoconductive member according to claim 33,wherein the amorphous material constituting the second layer (II) is anamorphous material represented by the following formula:

    a-(Si.sub.x O.sub.1-x).sub.y (H,X).sub.1-y

(where 0<x, y<1).
 67. A photoconductive member according to claim 33,wherein the second layer (II) has a layer thickness of 0.003 to 30μ. 68.An electrophotographic process comprising:applying a charge to thephotoconductive member of claim 1, and irradiating the chargedphotoconductive member with an electromagnetic wave carryinginformation, thereby forming an electrostatic image on thephotoconductive member.
 69. An electrophotographic processcomprising:applying a charge to the photoconductive member of claim 33,and irradiating the charged photoconductive member with anelectromagnetic wave carrying information, thereby forming anelectrostatic image on the photoconductive member.